/* Prototype JavaScript framework, version 1.5.0_rc1
 * (c) 2005 Sam Stephenson <sam@conio.net>
 *
 * Prototype is freely distributable under the terms of an MIT-style license.
 * For details, see the Prototype web site: http://prototype.conio.net/
 *
/*--------------------------------------------------------------------------*/

var Prototype = {
	Version: '1.5.0_rc1',
	BrowserFeatures: {
	XPath: !!document.evaluate
	},

	ScriptFragment: '(?:<script.*?>)((\n|\r|.)*?)(?:<\/script>)',
	emptyFunction: function() {},
	K: function(x) { return x }
}

var Class = {
	create: function() {
	return function() {
		this.initialize.apply(this, arguments);
	}
	}
}

var Abstract = new Object();

Object.extend = function(destination, source) {
	for (var property in source) {
	destination[property] = source[property];
	}
	return destination;
}

Object.extend(Object, {
	inspect: function(object) {
	try {
		if (object === undefined) return 'undefined';
		if (object === null) return 'null';
		return object.inspect ? object.inspect() : object.toString();
	} catch (e) {
		if (e instanceof RangeError) return '...';
		throw e;
	}
	},

	keys: function(object) {
	var keys = [];
	for (var property in object)
		keys.push(property);
	return keys;
	},

	values: function(object) {
	var values = [];
	for (var property in object)
		values.push(object[property]);
	return values;
	},

	clone: function(object) {
	return Object.extend({}, object);
	}
});

Function.prototype.bind = function() {
	var __method = this, args = $A(arguments), object = args.shift();
	return function() {
	return __method.apply(object, args.concat($A(arguments)));
	}
}

Function.prototype.bindAsEventListener = function(object) {
	var __method = this, args = $A(arguments), object = args.shift();
	return function(event) {
	return __method.apply(object, [( event || window.event)].concat(args).concat($A(arguments)));
	}
}

Object.extend(Number.prototype, {
	toColorPart: function() {
	var digits = this.toString(16);
	if (this < 16) return '0' + digits;
	return digits;
	},

	succ: function() {
	return this + 1;
	},

	times: function(iterator) {
	$R(0, this, true).each(iterator);
	return this;
	}
});

var Try = {
	these: function() {
	var returnValue;

	for (var i = 0; i < arguments.length; i++) {
		var lambda = arguments[i];
		try {
		returnValue = lambda();
		break;
		} catch (e) {}
	}

	return returnValue;
	}
}

/*----------------------------*/

var PeriodicalExecuter = Class.create();
PeriodicalExecuter.prototype = {
	initialize: function(callback, frequency) {
	this.callback = callback;
	this.frequency = frequency;
	this.currentlyExecuting = false;

	this.registerCallback();
	},

	registerCallback: function() {
	this.timer = setInterval(this.onTimerEvent.bind(this), this.frequency * 1000);
	},

	stop: function() {
	if (!this.timer) return;
	clearInterval(this.timer);
	this.timer = null;
	},

	onTimerEvent: function() {
	if (!this.currentlyExecuting) {
		try {
		this.currentlyExecuting = true;
		this.callback(this);
		} finally {
		this.currentlyExecuting = false;
		}
	}
	}
}

Object.extend(String.prototype, {
	gsub: function(pattern, replacement) {
	var result = '', source = this, match;
	replacement = arguments.callee.prepareReplacement(replacement);

	while (source.length > 0) {
		if (match = source.match(pattern)) {
		result += source.slice(0, match.index);
		result += (replacement(match) || '').toString();
		source = source.slice(match.index + match[0].length);
		} else {
		result += source, source = '';
		}
	}
	return result;
	},

	sub: function(pattern, replacement, count) {
	replacement = this.gsub.prepareReplacement(replacement);
	count = count === undefined ? 1 : count;

	return this.gsub(pattern, function(match) {
		if (--count < 0) return match[0];
		return replacement(match);
	});
	},

	scan: function(pattern, iterator) {
	this.gsub(pattern, iterator);
	return this;
	},

	truncate: function(length, truncation) {
	length = length || 30;
	truncation = truncation === undefined ? '...' : truncation;
	return this.length > length ?
		this.slice(0, length - truncation.length) + truncation : this;
	},

	strip: function() {
	return this.replace(/^\s+/, '').replace(/\s+$/, '');
	},

	stripTags: function() {
	return this.replace(/<\/?[^>]+>/gi, '');
	},

	stripScripts: function() {
	return this.replace(new RegExp(Prototype.ScriptFragment, 'img'), '');
	},

	extractScripts: function() {
	var matchAll = new RegExp(Prototype.ScriptFragment, 'img');
	var matchOne = new RegExp(Prototype.ScriptFragment, 'im');
	return (this.match(matchAll) || []).map(function(scriptTag) {
		return (scriptTag.match(matchOne) || ['', ''])[1];
	});
	},

	evalScripts: function() {
	return this.extractScripts().map(function(script) { return eval(script) });
	},

	escapeHTML: function() {
	var div = document.createElement('div');
	var text = document.createTextNode(this);
	div.appendChild(text);
	return div.innerHTML;
	},

	unescapeHTML: function() {
	var div = document.createElement('div');
	div.innerHTML = this.stripTags();
	return div.childNodes[0] ? div.childNodes[0].nodeValue : '';
	},

	toQueryParams: function() {
	var match = this.strip().match(/[^?]*$/)[0];
	if (!match) return {};
	var pairs = match.split('&');
	return pairs.inject({}, function(params, pairString) {
		var pair = pairString.split('=');
		var value = pair[1] ? decodeURIComponent(pair[1]) : undefined;
		params[decodeURIComponent(pair[0])] = value;
		return params;
	});
	},

	toArray: function() {
	return this.split('');
	},

	camelize: function() {
	var oStringList = this.split('-');
	if (oStringList.length == 1) return oStringList[0];

	var camelizedString = this.indexOf('-') == 0
		? oStringList[0].charAt(0).toUpperCase() + oStringList[0].substring(1)
		: oStringList[0];

	for (var i = 1, length = oStringList.length; i < length; i++) {
		var s = oStringList[i];
		camelizedString += s.charAt(0).toUpperCase() + s.substring(1);
	}

	return camelizedString;
	},

	inspect: function(useDoubleQuotes) {
	var escapedString = this.replace(/\\/g, '\\\\');
	if (useDoubleQuotes)
		return '"' + escapedString.replace(/"/g, '\\"') + '"';
	else
		return "'" + escapedString.replace(/'/g, '\\\'') + "'";
	}
});

String.prototype.gsub.prepareReplacement = function(replacement) {
	if (typeof replacement == 'function') return replacement;
	var template = new Template(replacement);
	return function(match) { return template.evaluate(match) };
}

String.prototype.parseQuery = String.prototype.toQueryParams;

var Template = Class.create();
Template.Pattern = /(^|.|\r|\n)(#\{(.*?)\})/;
Template.prototype = {
	initialize: function(template, pattern) {
	this.template = template.toString();
	this.pattern = pattern || Template.Pattern;
	},

	evaluate: function(object) {
	return this.template.gsub(this.pattern, function(match) {
		var before = match[1];
		if (before == '\\') return match[2];
		return before + (object[match[3]] || '').toString();
	});
	}
}

var $break	= new Object();
var $continue = new Object();

var Enumerable = {
	each: function(iterator) {
	var index = 0;
	try {
		this._each(function(value) {
		try {
			iterator(value, index++);
		} catch (e) {
			if (e != $continue) throw e;
		}
		});
	} catch (e) {
		if (e != $break) throw e;
	}
	return this;
	},

	eachSlice: function(number, iterator) {
	var index = -number, slices = [], array = this.toArray();
	while ((index += number) < array.length)
		slices.push(array.slice(index, index+number));
	return slices.collect(iterator || Prototype.K);
	},

	all: function(iterator) {
	var result = true;
	this.each(function(value, index) {
		result = result && !!(iterator || Prototype.K)(value, index);
		if (!result) throw $break;
	});
	return result;
	},

	any: function(iterator) {
	var result = false;
	this.each(function(value, index) {
		if (result = !!(iterator || Prototype.K)(value, index))
		throw $break;
	});
	return result;
	},

	collect: function(iterator) {
	var results = [];
	this.each(function(value, index) {
		results.push(iterator(value, index));
	});
	return results;
	},

	detect: function(iterator) {
	var result;
	this.each(function(value, index) {
		if (iterator(value, index)) {
		result = value;
		throw $break;
		}
	});
	return result;
	},

	findAll: function(iterator) {
	var results = [];
	this.each(function(value, index) {
		if (iterator(value, index))
		results.push(value);
	});
	return results;
	},

	grep: function(pattern, iterator) {
	var results = [];
	this.each(function(value, index) {
		var stringValue = value.toString();
		if (stringValue.match(pattern))
		results.push((iterator || Prototype.K)(value, index));
	})
	return results;
	},

	include: function(object) {
	var found = false;
	this.each(function(value) {
		if (value == object) {
		found = true;
		throw $break;
		}
	});
	return found;
	},

	inGroupsOf: function(number, fillWith) {
	fillWith = fillWith || null;
	var results = this.eachSlice(number);
	if (results.length > 0) (number - results.last().length).times(function() {
		results.last().push(fillWith)
	});
	return results;
	},

	inject: function(memo, iterator) {
	this.each(function(value, index) {
		memo = iterator(memo, value, index);
	});
	return memo;
	},

	invoke: function(method) {
	var args = $A(arguments).slice(1);
	return this.collect(function(value) {
		return value[method].apply(value, args);
	});
	},

	max: function(iterator) {
	var result;
	this.each(function(value, index) {
		value = (iterator || Prototype.K)(value, index);
		if (result == undefined || value >= result)
		result = value;
	});
	return result;
	},

	min: function(iterator) {
	var result;
	this.each(function(value, index) {
		value = (iterator || Prototype.K)(value, index);
		if (result == undefined || value < result)
		result = value;
	});
	return result;
	},

	partition: function(iterator) {
	var trues = [], falses = [];
	this.each(function(value, index) {
		((iterator || Prototype.K)(value, index) ?
		trues : falses).push(value);
	});
	return [trues, falses];
	},

	pluck: function(property) {
	var results = [];
	this.each(function(value, index) {
		results.push(value[property]);
	});
	return results;
	},

	reject: function(iterator) {
	var results = [];
	this.each(function(value, index) {
		if (!iterator(value, index))
		results.push(value);
	});
	return results;
	},

	sortBy: function(iterator) {
	return this.collect(function(value, index) {
		return {value: value, criteria: iterator(value, index)};
	}).sort(function(left, right) {
		var a = left.criteria, b = right.criteria;
		return a < b ? -1 : a > b ? 1 : 0;
	}).pluck('value');
	},

	toArray: function() {
	return this.collect(Prototype.K);
	},

	zip: function() {
	var iterator = Prototype.K, args = $A(arguments);
	if (typeof args.last() == 'function')
		iterator = args.pop();

	var collections = [this].concat(args).map($A);
	return this.map(function(value, index) {
		return iterator(collections.pluck(index));
	});
	},

	inspect: function() {
	return '#<Enumerable:' + this.toArray().inspect() + '>';
	}
}

Object.extend(Enumerable, {
	map: Enumerable.collect,
	find: Enumerable.detect,
	select: Enumerable.findAll,
	member: Enumerable.include,
	entries: Enumerable.toArray
});
var $A = Array.from = function(iterable) {
	if (!iterable) return [];
	if (iterable.toArray) {
	return iterable.toArray();
	} else {
	var results = [];
	for (var i = 0, length = iterable.length; i < length; i++)
		results.push(iterable[i]);
	return results;
	}
}

Object.extend(Array.prototype, Enumerable);

if (!Array.prototype._reverse)
	Array.prototype._reverse = Array.prototype.reverse;

Object.extend(Array.prototype, {
	_each: function(iterator) {
	for (var i = 0, length = this.length; i < length; i++)
		iterator(this[i]);
	},

	clear: function() {
	this.length = 0;
	return this;
	},

	first: function() {
	return this[0];
	},

	last: function() {
	return this[this.length - 1];
	},

	compact: function() {
	return this.select(function(value) {
		return value != undefined || value != null;
	});
	},

	flatten: function() {
	return this.inject([], function(array, value) {
		return array.concat(value && value.constructor == Array ?
		value.flatten() : [value]);
	});
	},

	without: function() {
	var values = $A(arguments);
	return this.select(function(value) {
		return !values.include(value);
	});
	},

	indexOf: function(object) {
	for (var i = 0, length = this.length; i < length; i++)
		if (this[i] == object) return i;
	return -1;
	},

	reverse: function(inline) {
	return (inline !== false ? this : this.toArray())._reverse();
	},

	reduce: function() {
	return this.length > 1 ? this : this[0];
	},

	uniq: function() {
	return this.inject([], function(array, value) {
		return array.include(value) ? array : array.concat([value]);
	});
	},

	clone: function() {
	return [].concat(this);
	},

	inspect: function() {
	return '[' + this.map(Object.inspect).join(', ') + ']';
	}
});

Array.prototype.toArray = Array.prototype.clone;
var Hash = {
	_each: function(iterator) {
	for (var key in this) {
		var value = this[key];
		if (typeof value == 'function') continue;

		var pair = [key, value];
		pair.key = key;
		pair.value = value;
		iterator(pair);
	}
	},

	keys: function() {
	return this.pluck('key');
	},

	values: function() {
	return this.pluck('value');
	},

	merge: function(hash) {
	return $H(hash).inject(this, function(mergedHash, pair) {
		mergedHash[pair.key] = pair.value;
		return mergedHash;
	});
	},

	toQueryString: function() {
	return this.map(function(pair) {
		if (!pair.value && pair.value !== 0) pair[1] = '';
		if (!pair.key) return;
		return pair.map(encodeURIComponent).join('=');
	}).join('&');
	},

	inspect: function() {
	return '#<Hash:{' + this.map(function(pair) {
		return pair.map(Object.inspect).join(': ');
	}).join(', ') + '}>';
	}
}

function $H(object) {
	var hash = Object.extend({}, object || {});
	Object.extend(hash, Enumerable);
	Object.extend(hash, Hash);
	return hash;
}
ObjectRange = Class.create();
Object.extend(ObjectRange.prototype, Enumerable);
Object.extend(ObjectRange.prototype, {
	initialize: function(start, end, exclusive) {
	this.start = start;
	this.end = end;
	this.exclusive = exclusive;
	},

	_each: function(iterator) {
	var value = this.start;
	while (this.include(value)) {
		iterator(value);
		value = value.succ();
	}
	},

	include: function(value) {
	if (value < this.start)
		return false;
	if (this.exclusive)
		return value < this.end;
	return value <= this.end;
	}
});

var $R = function(start, end, exclusive) {
	return new ObjectRange(start, end, exclusive);
}

var Ajax = {
	getTransport: function() {
	return Try.these(
		function() {return new XMLHttpRequest()},
		function() {return new ActiveXObject('Msxml2.XMLHTTP')},
		function() {return new ActiveXObject('Microsoft.XMLHTTP')}
	) || false;
	},

	activeRequestCount: 0
}

Ajax.Responders = {
	responders: [],

	_each: function(iterator) {
	this.responders._each(iterator);
	},

	register: function(responder) {
	if (!this.include(responder))
		this.responders.push(responder);
	},

	unregister: function(responder) {
	this.responders = this.responders.without(responder);
	},

	dispatch: function(callback, request, transport, json) {
	this.each(function(responder) {
		if (typeof responder[callback] == 'function') {
		try {
			responder[callback].apply(responder, [request, transport, json]);
		} catch (e) {}
		}
	});
	}
};

Object.extend(Ajax.Responders, Enumerable);

Ajax.Responders.register({
	onCreate: function() {
	Ajax.activeRequestCount++;
	},
	onComplete: function() {
	Ajax.activeRequestCount--;
	}
});

Ajax.Base = function() {};
Ajax.Base.prototype = {
	setOptions: function(options) {
	this.options = {
		method: 'post',
		asynchronous: true,
		contentType: 'application/x-www-form-urlencoded',
		encoding: 'UTF-8',
		parameters:	 ''
	}
	Object.extend(this.options, options || {});

	this.options.method = this.options.method.toLowerCase();
	this.options.parameters = $H(typeof this.options.parameters == 'string' ?
		this.options.parameters.toQueryParams() : this.options.parameters);
	}
}

Ajax.Request = Class.create();
Ajax.Request.Events = ['Uninitialized', 'Loading', 'Loaded', 'Interactive', 'Complete'];

Ajax.Request.prototype = Object.extend(new Ajax.Base(), {
	initialize: function(url, options) {
	this.transport = Ajax.getTransport();
	this.setOptions(options);
	this.request(url);
	},

	request: function(url) {
	var params = this.options.parameters;
	if (params.any()) params['_'] = '';

	if (!['get', 'post'].include(this.options.method)) {
		// simulate other verbs over post
		params['_method'] = this.options.method;
		this.options.method = 'post';
	}

	this.url = url;

	// when GET, append parameters to URL
	if (this.options.method == 'get' && params.any())
		this.url += (this.url.indexOf('?') >= 0 ? '&' : '?') +
		params.toQueryString();

	try {
		Ajax.Responders.dispatch('onCreate', this, this.transport);

		this.transport.open(this.options.method.toUpperCase(), this.url,
		this.options.asynchronous, this.options.username,
		this.options.password);

		if (this.options.asynchronous)
		setTimeout(function() { this.respondToReadyState(1) }.bind(this), 10);

		this.transport.onreadystatechange = this.onStateChange.bind(this);
		this.setRequestHeaders();

		var body = this.options.method == 'post' ?
		(this.options.postBody || params.toQueryString()) : null;

		this.transport.send(body);

		/* Force Firefox to handle ready state 4 for synchronous requests */
		if (!this.options.asynchronous && this.transport.overrideMimeType)
		this.onStateChange();
	}
	catch (e) {
		this.dispatchException(e);
	}
	},

	onStateChange: function() {
	var readyState = this.transport.readyState;
	if (readyState > 1)
		this.respondToReadyState(this.transport.readyState);
	},

	setRequestHeaders: function() {
	var headers = {
		'X-Requested-With': 'XMLHttpRequest',
		'X-Prototype-Version': Prototype.Version,
		'Accept': 'text/javascript, text/html, application/xml, text/xml, */*'
	};

	if (this.options.method == 'post') {
		headers['Content-type'] = this.options.contentType +
		(this.options.encoding ? '; charset=' + this.options.encoding : '');

		/* Force "Connection: close" for older Mozilla browsers to work
		 * around a bug where XMLHttpRequest sends an incorrect
		 * Content-length header. See Mozilla Bugzilla #246651.
		 */
		if (this.transport.overrideMimeType &&
			(navigator.userAgent.match(/Gecko\/(\d{4})/) || [0,2005])[1] < 2005)
			headers['Connection'] = 'close';
	}

	// user-defined headers
	if (typeof this.options.requestHeaders == 'object') {
		var extras = this.options.requestHeaders;

		if (typeof extras.push == 'function')
		for (var i = 0; i < extras.length; i += 2)
			headers[extras[i]] = extras[i+1];
		else
		$H(extras).each(function(pair) { headers[pair.key] = pair.value });
	}

	for (var name in headers)
		this.transport.setRequestHeader(name, headers[name]);
	},

	success: function() {
	return !this.transport.status
		|| (this.transport.status >= 200 && this.transport.status < 300);
	},

	respondToReadyState: function(readyState) {
	var state = Ajax.Request.Events[readyState];
	var transport = this.transport, json = this.evalJSON();

	if (state == 'Complete') {
		try {
		(this.options['on' + this.transport.status]
		 || this.options['on' + (this.success() ? 'Success' : 'Failure')]
		 || Prototype.emptyFunction)(transport, json);
		} catch (e) {
		this.dispatchException(e);
		}
	}

	try {
		(this.options['on' + state] || Prototype.emptyFunction)(transport, json);
		Ajax.Responders.dispatch('on' + state, this, transport, json);
	} catch (e) {
		this.dispatchException(e);
	}

	if (state == 'Complete') {
		if ((this.getHeader('Content-type') || '').strip().
		match(/^(text|application)\/(x-)?(java|ecma)script(;.*)?$/i))
			this.evalResponse();

		// avoid memory leak in MSIE: clean up
		this.transport.onreadystatechange = Prototype.emptyFunction;
	}
	},

	getHeader: function(name) {
	try {
		return this.transport.getResponseHeader(name);
	} catch (e) { return null }
	},

	evalJSON: function() {
	try {
		var json = this.getHeader('X-JSON');
		return json ? eval('(' + json + ')') : null;
	} catch (e) { return null }
	},

	evalResponse: function() {
	try {
		return eval(this.transport.responseText);
	} catch (e) {
		this.dispatchException(e);
	}
	},

	dispatchException: function(exception) {
	(this.options.onException || Prototype.emptyFunction)(this, exception);
	Ajax.Responders.dispatch('onException', this, exception);
	}
});

Ajax.Updater = Class.create();

Object.extend(Object.extend(Ajax.Updater.prototype, Ajax.Request.prototype), {
	initialize: function(container, url, options) {
	this.container = {
		success: (container.success || container),
		failure: (container.failure || (container.success ? null : container))
	}

	this.transport = Ajax.getTransport();
	this.setOptions(options);

	var onComplete = this.options.onComplete || Prototype.emptyFunction;
	this.options.onComplete = (function(transport, param) {
		this.updateContent();
		onComplete(transport, param);
	}).bind(this);

	this.request(url);
	},

	updateContent: function() {
	var receiver = this.container[this.success() ? 'success' : 'failure'];
	var response = this.transport.responseText;

	if (!this.options.evalScripts) response = response.stripScripts();

	if (receiver = $(receiver)) {
		if (this.options.insertion)
		new this.options.insertion(receiver, response);
		else
		receiver.update(response);
	}

	if (this.success()) {
		if (this.onComplete)
		setTimeout(this.onComplete.bind(this), 10);
	}
	}
});

Ajax.PeriodicalUpdater = Class.create();
Ajax.PeriodicalUpdater.prototype = Object.extend(new Ajax.Base(), {
	initialize: function(container, url, options) {
	this.setOptions(options);
	this.onComplete = this.options.onComplete;

	this.frequency = (this.options.frequency || 2);
	this.decay = (this.options.decay || 1);

	this.updater = {};
	this.container = container;
	this.url = url;

	this.start();
	},

	start: function() {
	this.options.onComplete = this.updateComplete.bind(this);
	this.onTimerEvent();
	},

	stop: function() {
	this.updater.options.onComplete = undefined;
	clearTimeout(this.timer);
	(this.onComplete || Prototype.emptyFunction).apply(this, arguments);
	},

	updateComplete: function(request) {
	if (this.options.decay) {
		this.decay = (request.responseText == this.lastText ?
		this.decay * this.options.decay : 1);

		this.lastText = request.responseText;
	}
	this.timer = setTimeout(this.onTimerEvent.bind(this),
		this.decay * this.frequency * 1000);
	},

	onTimerEvent: function() {
	this.updater = new Ajax.Updater(this.container, this.url, this.options);
	}
});
function $(element) {
	if (arguments.length > 1) {
	for (var i = 0, elements = [], length = arguments.length; i < length; i++)
		elements.push($(arguments[i]));
	return elements;
	}
	if (typeof element == 'string')
	element = document.getElementById(element);
	return Element.extend(element);
}

if (Prototype.BrowserFeatures.XPath) {
	document._getElementsByXPath = function(expression, parentElement) {
	var results = [];
	var query = document.evaluate(expression, $(parentElement) || document,
		null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);
	for (var i = 0, len = query.snapshotLength; i < len; i++)
		results.push(query.snapshotItem(i));
	return results;
	}
}

document.getElementsByClassName = function(className, parentElement) {
	if (Prototype.BrowserFeatures.XPath) {
	var q = ".//*[contains(concat(' ', @class, ' '), ' " + className + " ')]";
	return document._getElementsByXPath(q, parentElement);
	} else {
	var children = ($(parentElement) || document.body).getElementsByTagName('*');
	var elements = [], child;
	for (var i = 0, length = children.length; i < length; i++) {
		child = children[i];
		if (Element.hasClassName(child, className))
		elements.push(Element.extend(child));
	}
	return elements;
	}
}

/*----------------------------*/

if (!window.Element)
	var Element = new Object();

Element.extend = function(element) {
	if (!element) return;
	if (_nativeExtensions || element.nodeType == 3) return element;

	if (!element._extended && element.tagName && element != window) {
	var methods = Object.clone(Element.Methods), cache = Element.extend.cache;

	if (element.tagName == 'FORM')
		Object.extend(methods, Form.Methods);
	if (['INPUT', 'TEXTAREA', 'SELECT'].include(element.tagName))
		Object.extend(methods, Form.Element.Methods);

	for (var property in methods) {
		var value = methods[property];
		if (typeof value == 'function')
		element[property] = cache.findOrStore(value);
	}

	var methods = Object.clone(Element.Methods.Simulated), cache = Element.extend.cache;
	for (var property in methods) {
		var value = methods[property];
		if ('function' == typeof value && !(property in element))
		element[property] = cache.findOrStore(value);
	}
	}

	element._extended = true;
	return element;
}

Element.extend.cache = {
	findOrStore: function(value) {
	return this[value] = this[value] || function() {
		return value.apply(null, [this].concat($A(arguments)));
	}
	}
}

Element.Methods = {
	visible: function(element) {
	return $(element).style.display != 'none';
	},

	toggle: function(element) {
	element = $(element);
	Element[Element.visible(element) ? 'hide' : 'show'](element);
	return element;
	},

	hide: function(element) {
	$(element).style.display = 'none';
	return element;
	},

	show: function(element) {
	$(element).style.display = '';
	return element;
	},

	remove: function(element) {
	element = $(element);
	element.parentNode.removeChild(element);
	return element;
	},

	update: function(element, html) {
	html = typeof html == 'undefined' ? '' : html.toString();
	$(element).innerHTML = html.stripScripts();
	setTimeout(function() {html.evalScripts()}, 10);
	return element;
	},

	replace: function(element, html) {
	element = $(element);
	if (element.outerHTML) {
		element.outerHTML = html.stripScripts();
	} else {
		var range = element.ownerDocument.createRange();
		range.selectNodeContents(element);
		element.parentNode.replaceChild(
		range.createContextualFragment(html.stripScripts()), element);
	}
	setTimeout(function() {html.evalScripts()}, 10);
	return element;
	},

	inspect: function(element) {
	element = $(element);
	var result = '<' + element.tagName.toLowerCase();
	$H({'id': 'id', 'className': 'class'}).each(function(pair) {
		var property = pair.first(), attribute = pair.last();
		var value = (element[property] || '').toString();
		if (value) result += ' ' + attribute + '=' + value.inspect(true);
	});
	return result + '>';
	},

	recursivelyCollect: function(element, property) {
	element = $(element);
	var elements = [];
	while (element = element[property])
		if (element.nodeType == 1)
		elements.push(Element.extend(element));
	return elements;
	},

	ancestors: function(element) {
	return $(element).recursivelyCollect('parentNode');
	},

	descendants: function(element) {
	element = $(element);
	return $A(element.getElementsByTagName('*'));
	},

	previousSiblings: function(element) {
	return $(element).recursivelyCollect('previousSibling');
	},

	nextSiblings: function(element) {
	return $(element).recursivelyCollect('nextSibling');
	},

	siblings: function(element) {
	element = $(element);
	return element.previousSiblings().reverse().concat(element.nextSiblings());
	},

	match: function(element, selector) {
	element = $(element);
	if (typeof selector == 'string')
		selector = new Selector(selector);
	return selector.match(element);
	},

	up: function(element, expression, index) {
	return Selector.findElement($(element).ancestors(), expression, index);
	},

	down: function(element, expression, index) {
	return Selector.findElement($(element).descendants(), expression, index);
	},

	previous: function(element, expression, index) {
	return Selector.findElement($(element).previousSiblings(), expression, index);
	},

	next: function(element, expression, index) {
	return Selector.findElement($(element).nextSiblings(), expression, index);
	},

	getElementsBySelector: function() {
	var args = $A(arguments), element = $(args.shift());
	return Selector.findChildElements(element, args);
	},

	getElementsByClassName: function(element, className) {
	element = $(element);
	return document.getElementsByClassName(className, element);
	},

	getHeight: function(element) {
	element = $(element);
	return element.offsetHeight;
	},

	classNames: function(element) {
	return new Element.ClassNames(element);
	},

	hasClassName: function(element, className) {
	if (!(element = $(element))) return;
	var elementClassName = element.className;
	if (elementClassName.length == 0) return false;
	if (elementClassName == className ||
		elementClassName.match(new RegExp("(^|\\s)" + className + "(\\s|$)")))
		return true;
	return false;
	},

	addClassName: function(element, className) {
	if (!(element = $(element))) return;
	Element.classNames(element).add(className);
	return element;
	},

	removeClassName: function(element, className) {
	if (!(element = $(element))) return;
	Element.classNames(element).remove(className);
	return element;
	},

	observe: function() {
	Event.observe.apply(Event, arguments);
	return $A(arguments).first();
	},

	stopObserving: function() {
	Event.stopObserving.apply(Event, arguments);
	return $A(arguments).first();
	},

	// removes whitespace-only text node children
	cleanWhitespace: function(element) {
	element = $(element);
	var node = element.firstChild;
	while (node) {
		var nextNode = node.nextSibling;
		if (node.nodeType == 3 && !/\S/.test(node.nodeValue))
		element.removeChild(node);
		node = nextNode;
	}
	return element;
	},

	empty: function(element) {
	return $(element).innerHTML.match(/^\s*$/);
	},

	childOf: function(element, ancestor) {
	element = $(element), ancestor = $(ancestor);
	while (element = element.parentNode)
		if (element == ancestor) return true;
	return false;
	},

	scrollTo: function(element) {
	element = $(element);
	var x = element.x ? element.x : element.offsetLeft,
		y = element.y ? element.y : element.offsetTop;
	window.scrollTo(x, y);
	return element;
	},

	getStyle: function(element, style) {
	element = $(element);
	var value = element.style[style.camelize()];
	if (!value) {
		if (document.defaultView && document.defaultView.getComputedStyle) {
		var css = document.defaultView.getComputedStyle(element, null);
		value = css ? css.getPropertyValue(style) : null;
		} else if (element.currentStyle) {
		value = element.currentStyle[style.camelize()];
		}
	}

	if (window.opera && ['left', 'top', 'right', 'bottom'].include(style))
		if (Element.getStyle(element, 'position') == 'static') value = 'auto';

	return value == 'auto' ? null : value;
	},

	setStyle: function(element, style) {
	element = $(element);
	for (var name in style)
		element.style[name.camelize()] = style[name];
	return element;
	},

	getDimensions: function(element) {
	element = $(element);
	if (Element.getStyle(element, 'display') != 'none')
		return {width: element.offsetWidth, height: element.offsetHeight};

	// All *Width and *Height properties give 0 on elements with display none,
	// so enable the element temporarily
	var els = element.style;
	var originalVisibility = els.visibility;
	var originalPosition = els.position;
	els.visibility = 'hidden';
	els.position = 'absolute';
	els.display = '';
	var originalWidth = element.clientWidth;
	var originalHeight = element.clientHeight;
	els.display = 'none';
	els.position = originalPosition;
	els.visibility = originalVisibility;
	return {width: originalWidth, height: originalHeight};
	},

	makePositioned: function(element) {
	element = $(element);
	var pos = Element.getStyle(element, 'position');
	if (pos == 'static' || !pos) {
		element._madePositioned = true;
		element.style.position = 'relative';
		// Opera returns the offset relative to the positioning context, when an
		// element is position relative but top and left have not been defined
		if (window.opera) {
		element.style.top = 0;
		element.style.left = 0;
		}
	}
	return element;
	},

	undoPositioned: function(element) {
	element = $(element);
	if (element._madePositioned) {
		element._madePositioned = undefined;
		element.style.position =
		element.style.top =
		element.style.left =
		element.style.bottom =
		element.style.right = '';
	}
	return element;
	},

	makeClipping: function(element) {
	element = $(element);
	if (element._overflow) return element;
	element._overflow = element.style.overflow || 'auto';
	if ((Element.getStyle(element, 'overflow') || 'visible') != 'hidden')
		element.style.overflow = 'hidden';
	return element;
	},

	undoClipping: function(element) {
	element = $(element);
	if (!element._overflow) return element;
	element.style.overflow = element._overflow == 'auto' ? '' : element._overflow;
	element._overflow = null;
	return element;
	}
}

Element.Methods.Simulated = {
	hasAttribute: function(element, attribute) {
	return $(element).getAttributeNode(attribute).specified;
	}
}

// IE is missing .innerHTML support for TABLE-related elements
if(document.all){
	Element.Methods.update = function(element, html) {
	element = $(element);
	html = typeof html == 'undefined' ? '' : html.toString();
	var tagName = element.tagName.toUpperCase();
	if (['THEAD','TBODY','TR','TD'].indexOf(tagName) > -1) {
		var div = document.createElement('div');
		switch (tagName) {
		case 'THEAD':
		case 'TBODY':
			div.innerHTML = '<table><tbody>' + html.stripScripts() + '</tbody></table>';
			depth = 2;
			break;
		case 'TR':
			div.innerHTML = '<table><tbody><tr>' + html.stripScripts() + '</tr></tbody></table>';
			depth = 3;
			break;
		case 'TD':
			div.innerHTML = '<table><tbody><tr><td>' + html.stripScripts() + '</td></tr></tbody></table>';
			depth = 4;
		}
		$A(element.childNodes).each(function(node){
		element.removeChild(node)
		});
		depth.times(function(){ div = div.firstChild });

		$A(div.childNodes).each(
		function(node){ element.appendChild(node) });
	} else {
		element.innerHTML = html.stripScripts();
	}
	setTimeout(function() {html.evalScripts()}, 10);
	return element;
	}
}

Object.extend(Element, Element.Methods);

var _nativeExtensions = false;

if(/Konqueror|Safari|KHTML/.test(navigator.userAgent))
	['', 'Form', 'Input', 'TextArea', 'Select'].each(function(tag) {
	var className = 'HTML' + tag + 'Element';
	if(window[className]) return;
	var klass = window[className] = {};
	klass.prototype = document.createElement(tag ? tag.toLowerCase() : 'div').__proto__;
	});

Element.addMethods = function(methods) {
	Object.extend(Element.Methods, methods || {});

	function copy(methods, destination, onlyIfAbsent) {
	onlyIfAbsent = onlyIfAbsent || false;
	var cache = Element.extend.cache;
	for (var property in methods) {
		var value = methods[property];
		if (!onlyIfAbsent || !(property in destination))
		destination[property] = cache.findOrStore(value);
	}
	}

	if (typeof HTMLElement != 'undefined') {
	copy(Element.Methods, HTMLElement.prototype);
	copy(Element.Methods.Simulated, HTMLElement.prototype, true);
	copy(Form.Methods, HTMLFormElement.prototype);
	[HTMLInputElement, HTMLTextAreaElement, HTMLSelectElement].each(function(klass) {
		copy(Form.Element.Methods, klass.prototype);
	});
	_nativeExtensions = true;
	}
}

var Toggle = new Object();
Toggle.display = Element.toggle;

/*---------------------------*/

Abstract.Insertion = function(adjacency) {
	this.adjacency = adjacency;
}

Abstract.Insertion.prototype = {
	initialize: function(element, content) {
	this.element = $(element);
	this.content = content.stripScripts();

	if (this.adjacency && this.element.insertAdjacentHTML) {
		try {
		this.element.insertAdjacentHTML(this.adjacency, this.content);
		} catch (e) {
		var tagName = this.element.tagName.toLowerCase();
		if (tagName == 'tbody' || tagName == 'tr') {
			this.insertContent(this.contentFromAnonymousTable());
		} else {
			throw e;
		}
		}
	} else {
		this.range = this.element.ownerDocument.createRange();
		if (this.initializeRange) this.initializeRange();
		this.insertContent([this.range.createContextualFragment(this.content)]);
	}

	setTimeout(function() {content.evalScripts()}, 10);
	},

	contentFromAnonymousTable: function() {
	var div = document.createElement('div');
	div.innerHTML = '<table><tbody>' + this.content + '</tbody></table>';
	return $A(div.childNodes[0].childNodes[0].childNodes);
	}
}

var Insertion = new Object();

Insertion.Before = Class.create();
Insertion.Before.prototype = Object.extend(new Abstract.Insertion('beforeBegin'), {
	initializeRange: function() {
	this.range.setStartBefore(this.element);
	},

	insertContent: function(fragments) {
	fragments.each((function(fragment) {
		this.element.parentNode.insertBefore(fragment, this.element);
	}).bind(this));
	}
});

Insertion.Top = Class.create();
Insertion.Top.prototype = Object.extend(new Abstract.Insertion('afterBegin'), {
	initializeRange: function() {
	this.range.selectNodeContents(this.element);
	this.range.collapse(true);
	},

	insertContent: function(fragments) {
	fragments.reverse(false).each((function(fragment) {
		this.element.insertBefore(fragment, this.element.firstChild);
	}).bind(this));
	}
});

Insertion.Bottom = Class.create();
Insertion.Bottom.prototype = Object.extend(new Abstract.Insertion('beforeEnd'), {
	initializeRange: function() {
	this.range.selectNodeContents(this.element);
	this.range.collapse(this.element);
	},

	insertContent: function(fragments) {
	fragments.each((function(fragment) {
		this.element.appendChild(fragment);
	}).bind(this));
	}
});

Insertion.After = Class.create();
Insertion.After.prototype = Object.extend(new Abstract.Insertion('afterEnd'), {
	initializeRange: function() {
	this.range.setStartAfter(this.element);
	},

	insertContent: function(fragments) {
	fragments.each((function(fragment) {
		this.element.parentNode.insertBefore(fragment,
		this.element.nextSibling);
	}).bind(this));
	}
});

/*---------------------------*/

Element.ClassNames = Class.create();
Element.ClassNames.prototype = {
	initialize: function(element) {
	this.element = $(element);
	},

	_each: function(iterator) {
	this.element.className.split(/\s+/).select(function(name) {
		return name.length > 0;
	})._each(iterator);
	},

	set: function(className) {
	this.element.className = className;
	},

	add: function(classNameToAdd) {
	if (this.include(classNameToAdd)) return;
	this.set($A(this).concat(classNameToAdd).join(' '));
	},

	remove: function(classNameToRemove) {
	if (!this.include(classNameToRemove)) return;
	this.set($A(this).without(classNameToRemove).join(' '));
	},

	toString: function() {
	return $A(this).join(' ');
	}
}

Object.extend(Element.ClassNames.prototype, Enumerable);
var Selector = Class.create();
Selector.prototype = {
	initialize: function(expression) {
	this.params = {classNames: []};
	this.expression = expression.toString().strip();
	this.parseExpression();
	this.compileMatcher();
	},

	parseExpression: function() {
	function abort(message) { throw 'Parse error in selector: ' + message; }

	if (this.expression == '') abort('empty expression');

	var params = this.params, expr = this.expression, match, modifier, clause, rest;
	while (match = expr.match(/^(.*)\[([a-z0-9_:-]+?)(?:([~\|!]?=)(?:"([^"]*)"|([^\]\s]*)))?\]$/i)) {
		params.attributes = params.attributes || [];
		params.attributes.push({name: match[2], operator: match[3], value: match[4] || match[5] || ''});
		expr = match[1];
	}

	if (expr == '*') return this.params.wildcard = true;

	while (match = expr.match(/^([^a-z0-9_-])?([a-z0-9_-]+)(.*)/i)) {
		modifier = match[1], clause = match[2], rest = match[3];
		switch (modifier) {
		case '#': params.id = clause; break;
		case '.': params.classNames.push(clause); break;
		case '':
		case undefined: params.tagName = clause.toUpperCase(); break;
		default:		abort(expr.inspect());
		}
		expr = rest;
	}

	if (expr.length > 0) abort(expr.inspect());
	},

	buildMatchExpression: function() {
	var params = this.params, conditions = [], clause;

	if (params.wildcard)
		conditions.push('true');
	if (clause = params.id)
		conditions.push('element.id == ' + clause.inspect());
	if (clause = params.tagName)
		conditions.push('element.tagName.toUpperCase() == ' + clause.inspect());
	if ((clause = params.classNames).length > 0)
		for (var i = 0; i < clause.length; i++)
		conditions.push('Element.hasClassName(element, ' + clause[i].inspect() + ')');
	if (clause = params.attributes) {
		clause.each(function(attribute) {
		var value = 'element.getAttribute(' + attribute.name.inspect() + ')';
		var splitValueBy = function(delimiter) {
			return value + ' && ' + value + '.split(' + delimiter.inspect() + ')';
		}

		switch (attribute.operator) {
			case '=': conditions.push(value + ' == ' + attribute.value.inspect()); break;
			case '~=': conditions.push(splitValueBy(' ') + '.include(' + attribute.value.inspect() + ')'); break;
			case '|=': conditions.push(
							splitValueBy('-') + '.first().toUpperCase() == ' + attribute.value.toUpperCase().inspect()
			); break;
			case '!=': conditions.push(value + ' != ' + attribute.value.inspect()); break;
			case '':
			case undefined: conditions.push(value + ' != null'); break;
			default: throw 'Unknown operator ' + attribute.operator + ' in selector';
		}
		});
	}

	return conditions.join(' && ');
	},

	compileMatcher: function() {
	this.match = new Function('element', 'if (!element.tagName) return false; \
		return ' + this.buildMatchExpression());
	},

	findElements: function(scope) {
	var element;

	if (element = $(this.params.id))
		if (this.match(element))
		if (!scope || Element.childOf(element, scope))
			return [element];

	scope = (scope || document).getElementsByTagName(this.params.tagName || '*');

	var results = [];
	for (var i = 0, length = scope.length; i < length; i++)
		if (this.match(element = scope[i]))
		results.push(Element.extend(element));

	return results;
	},

	toString: function() {
	return this.expression;
	}
}

Object.extend(Selector, {
	matchElements: function(elements, expression) {
	var selector = new Selector(expression);
	return elements.select(selector.match.bind(selector)).collect(Element.extend);
	},

	findElement: function(elements, expression, index) {
	if (typeof expression == 'number') index = expression, expression = false;
	return Selector.matchElements(elements, expression || '*')[index || 0];
	},

	findChildElements: function(element, expressions) {
	return expressions.map(function(expression) {
		return expression.strip().split(/\s+/).inject([null], function(results, expr) {
		var selector = new Selector(expr);
		return results.inject([], function(elements, result) {
			return elements.concat(selector.findElements(result || element));
		});
		});
	}).flatten();
	}
});

function $$() {
	return Selector.findChildElements(document, $A(arguments));
}
var Form = {
	reset: function(form) {
	$(form).reset();
	return form;
	},

	serializeElements: function(elements) {
	return elements.inject([], function(queryComponents, element) {
		var queryComponent = Form.Element.serialize(element);
		if (queryComponent) queryComponents.push(queryComponent);
		return queryComponents;
	}).join('&');
	}
};

Form.Methods = {
	serialize: function(form) {
	return Form.serializeElements($(form).getElements());
	},

	getElements: function(form) {
	return $A($(form).getElementsByTagName('*')).inject([],
		function(elements, child) {
		if (Form.Element.Serializers[child.tagName.toLowerCase()])
			elements.push(Element.extend(child));
		return elements;
		}
	);
	},

	getInputs: function(form, typeName, name) {
	form = $(form);
	var inputs = form.getElementsByTagName('input');

	if (!typeName && !name)
		return inputs;

	var matchingInputs = new Array();
	for (var i = 0, length = inputs.length; i < length; i++) {
		var input = inputs[i];
		if ((typeName && input.type != typeName) ||
			(name && input.name != name))
		continue;
		matchingInputs.push(Element.extend(input));
	}

	return matchingInputs;
	},

	disable: function(form) {
	form = $(form);
	form.getElements().each(function(element) {
		element.blur();
		element.disabled = 'true';
	});
	return form;
	},

	enable: function(form) {
	form = $(form);
	form.getElements().each(function(element) {
		element.disabled = '';
	});
	return form;
	},

	findFirstElement: function(form) {
	return $(form).getElements().find(function(element) {
		return element.type != 'hidden' && !element.disabled &&
		['input', 'select', 'textarea'].include(element.tagName.toLowerCase());
	});
	},

	focusFirstElement: function(form) {
	form = $(form);
	form.findFirstElement().activate();
	return form;
	}
}

Object.extend(Form, Form.Methods);

/*--------------------------------------------------------------------------*/

Form.Element = {
	focus: function(element) {
	$(element).focus();
	return element;
	},

	select: function(element) {
	$(element).select();
	return element;
	}
}

Form.Element.Methods = {
	serialize: function(element) {
	element = $(element);
	if (element.disabled) return '';
	var method = element.tagName.toLowerCase();
	var parameter = Form.Element.Serializers[method](element);

	if (parameter) {
		var key = encodeURIComponent(parameter[0]);
		if (key.length == 0) return;

		if (parameter[1].constructor != Array)
		parameter[1] = [parameter[1]];

		return parameter[1].map(function(value) {
		return key + '=' + encodeURIComponent(value);
		}).join('&');
	}
	},

	getValue: function(element) {
	element = $(element);
	var method = element.tagName.toLowerCase();
	var parameter = Form.Element.Serializers[method](element);

	if (parameter)
		return parameter[1];
	},

	clear: function(element) {
	$(element).value = '';
	return element;
	},

	present: function(element) {
	return $(element).value != '';
	},

	activate: function(element) {
	element = $(element);
	element.focus();
	if (element.select)
		element.select();
	return element;
	},

	disable: function(element) {
	element = $(element);
	element.disabled = true;
	return element;
	},

	enable: function(element) {
	element = $(element);
	element.blur();
	element.disabled = false;
	return element;
	}
}

Object.extend(Form.Element, Form.Element.Methods);
var Field = Form.Element;

/*--------------------------------------------------------------------------*/

Form.Element.Serializers = {
	input: function(element) {
	switch (element.type.toLowerCase()) {
		case 'checkbox':
		case 'radio':
		return Form.Element.Serializers.inputSelector(element);
		default:
		return Form.Element.Serializers.textarea(element);
	}
	return false;
	},

	inputSelector: function(element) {
	if (element.checked)
		return [element.name, element.value];
	},

	textarea: function(element) {
	return [element.name, element.value];
	},

	select: function(element) {
	return Form.Element.Serializers[element.type == 'select-one' ?
		'selectOne' : 'selectMany'](element);
	},

	selectOne: function(element) {
	var value = '', opt, index = element.selectedIndex;
	if (index >= 0) {
		opt = Element.extend(element.options[index]);
		// Uses the new potential extension if hasAttribute isn't native.
		value = opt.hasAttribute('value') ? opt.value : opt.text;
	}
	return [element.name, value];
	},

	selectMany: function(element) {
	var value = [];
	for (var i = 0; i < element.length; i++) {
		var opt = Element.extend(element.options[i]);
		if (opt.selected)
		// Uses the new potential extension if hasAttribute isn't native.
		value.push(opt.hasAttribute('value') ? opt.value : opt.text);
	}
	return [element.name, value];
	}
}

/*---------------------------*/

var $F = Form.Element.getValue;

/*---------------------------*/

Abstract.TimedObserver = function() {}
Abstract.TimedObserver.prototype = {
	initialize: function(element, frequency, callback) {
	this.frequency = frequency;
	this.element = $(element);
	this.callback = callback;

	this.lastValue = this.getValue();
	this.registerCallback();
	},

	registerCallback: function() {
	setInterval(this.onTimerEvent.bind(this), this.frequency * 1000);
	},

	onTimerEvent: function() {
	var value = this.getValue();
	if (this.lastValue != value) {
		this.callback(this.element, value);
		this.lastValue = value;
	}
	}
}

Form.Element.Observer = Class.create();
Form.Element.Observer.prototype = Object.extend(new Abstract.TimedObserver(), {
	getValue: function() {
	return Form.Element.getValue(this.element);
	}
});

Form.Observer = Class.create();
Form.Observer.prototype = Object.extend(new Abstract.TimedObserver(), {
	getValue: function() {
	return Form.serialize(this.element);
	}
});

/*---------------------------*/

Abstract.EventObserver = function() {}
Abstract.EventObserver.prototype = {
	initialize: function(element, callback) {
	this.element = $(element);
	this.callback = callback;

	this.lastValue = this.getValue();
	if (this.element.tagName.toLowerCase() == 'form')
		this.registerFormCallbacks();
	else
		this.registerCallback(this.element);
	},

	onElementEvent: function() {
	var value = this.getValue();
	if (this.lastValue != value) {
		this.callback(this.element, value);
		this.lastValue = value;
	}
	},

	registerFormCallbacks: function() {
	Form.getElements(this.element).each(this.registerCallback.bind(this));
	},

	registerCallback: function(element) {
	if (element.type) {
		switch (element.type.toLowerCase()) {
		case 'checkbox':
		case 'radio':
			Event.observe(element, 'click', this.onElementEvent.bind(this));
			break;
		default:
			Event.observe(element, 'change', this.onElementEvent.bind(this));
			break;
		}
	}
	}
}

Form.Element.EventObserver = Class.create();
Form.Element.EventObserver.prototype = Object.extend(new Abstract.EventObserver(), {
	getValue: function() {
	return Form.Element.getValue(this.element);
	}
});

Form.EventObserver = Class.create();
Form.EventObserver.prototype = Object.extend(new Abstract.EventObserver(), {
	getValue: function() {
	return Form.serialize(this.element);
	}
});
if (!window.Event) {
	var Event = new Object();
}

Object.extend(Event, {
	KEY_BACKSPACE: 8,
	KEY_TAB: 9,
	KEY_RETURN: 13,
	KEY_ESC: 27,
	KEY_LEFT: 37,
	KEY_UP: 38,
	KEY_RIGHT: 39,
	KEY_DOWN: 40,
	KEY_DELETE: 46,
	KEY_HOME: 36,
	KEY_END: 35,
	KEY_PAGEUP: 33,
	KEY_PAGEDOWN: 34,

	element: function(event) {
	return event.target || event.srcElement;
	},

	isLeftClick: function(event) {
	return (((event.which) && (event.which == 1)) ||
			((event.button) && (event.button == 1)));
	},

	pointerX: function(event) {
	return event.pageX || (event.clientX +
		(document.documentElement.scrollLeft || document.body.scrollLeft));
	},

	pointerY: function(event) {
	return event.pageY || (event.clientY +
		(document.documentElement.scrollTop || document.body.scrollTop));
	},

	stop: function(event) {
	if (event.preventDefault) {
		event.preventDefault();
		event.stopPropagation();
	} else {
		event.returnValue = false;
		event.cancelBubble = true;
	}
	},

	// find the first node with the given tagName, starting from the
	// node the event was triggered on; traverses the DOM upwards
	findElement: function(event, tagName) {
	var element = Event.element(event);
	while (element.parentNode && (!element.tagName ||
		(element.tagName.toUpperCase() != tagName.toUpperCase())))
		element = element.parentNode;
	return element;
	},

	observers: false,

	_observeAndCache: function(element, name, observer, useCapture) {
	if (!this.observers) this.observers = [];
	if (element.addEventListener) {
		this.observers.push([element, name, observer, useCapture]);
		element.addEventListener(name, observer, useCapture);
	} else if (element.attachEvent) {
		this.observers.push([element, name, observer, useCapture]);
		element.attachEvent('on' + name, observer);
	}
	},

	unloadCache: function() {
	if (!Event.observers) return;
	for (var i = 0, length = Event.observers.length; i < length; i++) {
		Event.stopObserving.apply(this, Event.observers[i]);
		Event.observers[i][0] = null;
	}
	Event.observers = false;
	},

	observe: function(element, name, observer, useCapture) {
	element = $(element);
	useCapture = useCapture || false;

	if (name == 'keypress' &&
		(navigator.appVersion.match(/Konqueror|Safari|KHTML/)
		|| element.attachEvent))
		name = 'keydown';

	Event._observeAndCache(element, name, observer, useCapture);
	},

	stopObserving: function(element, name, observer, useCapture) {
	element = $(element);
	useCapture = useCapture || false;

	if (name == 'keypress' &&
		(navigator.appVersion.match(/Konqueror|Safari|KHTML/)
		|| element.detachEvent))
		name = 'keydown';

	if (element.removeEventListener) {
		element.removeEventListener(name, observer, useCapture);
	} else if (element.detachEvent) {
		try {
		element.detachEvent('on' + name, observer);
		} catch (e) {}
	}
	}
});

/* prevent memory leaks in IE */
if (navigator.appVersion.match(/\bMSIE\b/))
	Event.observe(window, 'unload', Event.unloadCache, false);
var Position = {
	// set to true if needed, warning: firefox performance problems
	// NOT neeeded for page scrolling, only if draggable contained in
	// scrollable elements
	includeScrollOffsets: false,

	// must be called before calling withinIncludingScrolloffset, every time the
	// page is scrolled
	prepare: function() {
	this.deltaX = window.pageXOffset
				|| document.documentElement.scrollLeft
				|| document.body.scrollLeft
				|| 0;
	this.deltaY = window.pageYOffset
				|| document.documentElement.scrollTop
				|| document.body.scrollTop
				|| 0;
	},

	realOffset: function(element) {
	var valueT = 0, valueL = 0;
	do {
		valueT += element.scrollTop || 0;
		valueL += element.scrollLeft || 0;
		element = element.parentNode;
	} while (element);
	return [valueL, valueT];
	},

	cumulativeOffset: function(element) {
	var valueT = 0, valueL = 0;
	do {
		valueT += element.offsetTop || 0;
		valueL += element.offsetLeft || 0;
		element = element.offsetParent;
	} while (element);
	return [valueL, valueT];
	},

	positionedOffset: function(element) {
	var valueT = 0, valueL = 0;
	do {
		valueT += element.offsetTop || 0;
		valueL += element.offsetLeft || 0;
		element = element.offsetParent;
		if (element) {
		if(element.tagName=='BODY') break;
		var p = Element.getStyle(element, 'position');
		if (p == 'relative' || p == 'absolute') break;
		}
	} while (element);
	return [valueL, valueT];
	},

	offsetParent: function(element) {
	if (element.offsetParent) return element.offsetParent;
	if (element == document.body) return element;

	while ((element = element.parentNode) && element != document.body)
		if (Element.getStyle(element, 'position') != 'static')
		return element;

	return document.body;
	},

	// caches x/y coordinate pair to use with overlap
	within: function(element, x, y) {
	if (this.includeScrollOffsets)
		return this.withinIncludingScrolloffsets(element, x, y);
	this.xcomp = x;
	this.ycomp = y;
	this.offset = this.cumulativeOffset(element);

	return (y >= this.offset[1] &&
			y < this.offset[1] + element.offsetHeight &&
			x >= this.offset[0] &&
			x < this.offset[0] + element.offsetWidth);
	},

	withinIncludingScrolloffsets: function(element, x, y) {
	var offsetcache = this.realOffset(element);

	this.xcomp = x + offsetcache[0] - this.deltaX;
	this.ycomp = y + offsetcache[1] - this.deltaY;
	this.offset = this.cumulativeOffset(element);

	return (this.ycomp >= this.offset[1] &&
			this.ycomp < this.offset[1] + element.offsetHeight &&
			this.xcomp >= this.offset[0] &&
			this.xcomp < this.offset[0] + element.offsetWidth);
	},

	// within must be called directly before
	overlap: function(mode, element) {
	if (!mode) return 0;
	if (mode == 'vertical')
		return ((this.offset[1] + element.offsetHeight) - this.ycomp) /
		element.offsetHeight;
	if (mode == 'horizontal')
		return ((this.offset[0] + element.offsetWidth) - this.xcomp) /
		element.offsetWidth;
	},

	page: function(forElement) {
	var valueT = 0, valueL = 0;

	var element = forElement;
	do {
		valueT += element.offsetTop || 0;
		valueL += element.offsetLeft || 0;

		// Safari fix
		if (element.offsetParent==document.body)
		if (Element.getStyle(element,'position')=='absolute') break;

	} while (element = element.offsetParent);

	element = forElement;
	do {
		if (!window.opera || element.tagName=='BODY') {
		valueT -= element.scrollTop || 0;
		valueL -= element.scrollLeft || 0;
		}
	} while (element = element.parentNode);

	return [valueL, valueT];
	},

	clone: function(source, target) {
	var options = Object.extend({
		setLeft: true,
		setTop: true,
		setWidth: true,
		setHeight: true,
		offsetTop: 0,
		offsetLeft: 0
	}, arguments[2] || {})

	// find page position of source
	source = $(source);
	var p = Position.page(source);

	// find coordinate system to use
	target = $(target);
	var delta = [0, 0];
	var parent = null;
	// delta [0,0] will do fine with position: fixed elements,
	// position:absolute needs offsetParent deltas
	if (Element.getStyle(target,'position') == 'absolute') {
		parent = Position.offsetParent(target);
		delta = Position.page(parent);
	}

	// correct by body offsets (fixes Safari)
	if (parent == document.body) {
		delta[0] -= document.body.offsetLeft;
		delta[1] -= document.body.offsetTop;
	}

	// set position
	if(options.setLeft) target.style.left = (p[0] - delta[0] + options.offsetLeft) + 'px';
	if(options.setTop) target.style.top = (p[1] - delta[1] + options.offsetTop) + 'px';
	if(options.setWidth) target.style.width = source.offsetWidth + 'px';
	if(options.setHeight) target.style.height = source.offsetHeight + 'px';
	},

	absolutize: function(element) {
	element = $(element);
	if (element.style.position == 'absolute') return;
	Position.prepare();

	var offsets = Position.positionedOffset(element);
	var top	= offsets[1];
	var left = offsets[0];
	var width = element.clientWidth;
	var height = element.clientHeight;

	element._originalLeft = left - parseFloat(element.style.left || 0);
	element._originalTop = top - parseFloat(element.style.top || 0);
	element._originalWidth = element.style.width;
	element._originalHeight = element.style.height;

	element.style.position = 'absolute';
	element.style.top = top + 'px';;
	element.style.left = left + 'px';;
	element.style.width = width + 'px';;
	element.style.height = height + 'px';;
	},

	relativize: function(element) {
	element = $(element);
	if (element.style.position == 'relative') return;
	Position.prepare();

	element.style.position = 'relative';
	var top = parseFloat(element.style.top || 0) - (element._originalTop || 0);
	var left = parseFloat(element.style.left || 0) - (element._originalLeft || 0);

	element.style.top = top + 'px';
	element.style.left = left + 'px';
	element.style.height = element._originalHeight;
	element.style.width = element._originalWidth;
	}
}

// Safari returns margins on body which is incorrect if the child is absolutely
// positioned. For performance reasons, redefine Position.cumulativeOffset for
// KHTML/WebKit only.
if (/Konqueror|Safari|KHTML/.test(navigator.userAgent)) {
	Position.cumulativeOffset = function(element) {
	var valueT = 0, valueL = 0;
	do {
		valueT += element.offsetTop || 0;
		valueL += element.offsetLeft || 0;
		if (element.offsetParent == document.body)
		if (Element.getStyle(element, 'position') == 'absolute') break;

		element = element.offsetParent;
	} while (element);

	return [valueL, valueT];
	}
}

Element.addMethods();