var Post = new Object();
Post.SendForm = function(form, updateDiv)
{
	var query = Post.buildQuery(form);
	Ajax.Request(form.method, form.action, query, Post.OnResponse, updateDiv);

	busyStart('Post.SendForm:'+updateDiv);
}




//customised to send a post ajax request.  data must be in the form "key1=value1&key2=value3..."
Post.Send = function(queryString, url, updateDiv)
{
	Ajax.Request('post', url, queryString, Post.OnResponse, updateDiv);

	busyStart('Post.Send:'+url);
}



////////////  supporting functions  //////////////////////////////////////////////////


Post.OnResponse = function(responseText, updateDiv)
{
	if (updateDiv != null) {
		document.getElementById(updateDiv).innerHTML = responseText;
	}
	else {
		DisplayResponses(responseText);
	}

	busyStop();
}



Post.buildQuery = function(form)
{
	var query = "";
	for(var i=0; i<form.elements.length; i++)
	{
		var key = form.elements[i].name;
		var value = Post.getElementValue(form.elements[i]);
		if(key && value)
		{
			query += key +"="+ value +"&";
		}
	}
	return query;
}

Post.getElementValue = function(formElement)
{
	if(formElement.length != null) var type = formElement[0].type;
	if((typeof(type) == 'undefined') || (type == 0)) var type = formElement.type;

	switch(type)
	{
		case 'undefined': return;

		case 'radio':
			for(var x=0; x < formElement.length; x++)
				if(formElement[x].checked == true)
			return formElement[x].value;

		case 'select-multiple':
			var myArray = new Array();
			for(var x=0; x < formElement.length; x++)
				if(formElement[x].selected == true)
					myArray[myArray.length] = formElement[x].value;
			return myArray;

		case 'checkbox': return formElement.checked;

		default: return formElement.value;
	}
}


var Ajax = new Object();
Ajax.isUpdating = true;

Ajax.Request = function(method, url, query, callback, updateDiv)
{
	this.isUpdating = true;
	this.callbackMethod = callback;
	this.divToUpdate = updateDiv;
	this.request = (window.XMLHttpRequest)? new XMLHttpRequest(): new ActiveXObject("MSXML2.XMLHTTP");
	this.request.onreadystatechange = function() { Ajax.checkReadyState(); };

	if(method.toLowerCase() == 'get') url = url+"?"+query;
	this.request.open(method, url, true);
	this.request.setRequestHeader("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8");
	this.request.setRequestHeader("X-Requested-With", "XMLHttpRequest");
	this.request.send(query);
}

Ajax.checkReadyState = function(_id)
{
	switch(this.request.readyState)
	{
		case 1: break;
		case 2: break;
		case 3: break;
		case 4:
			this.isUpdating = false;
			this.callbackMethod(this.request.responseText, this.divToUpdate);
	}
}



function DisplayResponses(qs) { // optionally pass a querystring to parse
	this.params = {};

	if (qs == null) qs = location.search.substring(1, location.search.length);
	if (qs.length == 0) return;

// Turn <plus> back to <space>
// See: http://www.w3.org/TR/REC-html40/interact/forms.html#h-17.13.4.1
//	qs = qs.myDecode();
	var args = qs.split('&'); // parse out name/value pairs separated via &
	var $targets;

// split out each name=value pair
	for (var i = 0; i < args.length; i++) {
		var pair = args[i].split('=');
		var name = pair[0].myDecode();

		var value = pair[1].myDecode();

		this.params[name] = value;

		//assign values to the specified elements. "javascript" is a special case enabling the server to run client side code as an ajax response
		if (name == 'javascript') {
			eval(value);
		} else {
			//"name" is either a jQuery selector or an element id or class
			$targets = jQuery(name);
			if ($targets.length == 0) { $targets = jQuery('#'+name+', .'+name); }
			if ($targets.length != 0) {
				if ($targets.is(':checkbox')) {
					if (value == 1) {
						$targets.attr('checked', 'checked');	
					} else {
						$targets.removeAttr('checked');	
					}
				} else {
					$targets.fadeOut('fast').html(value).val(value).fadeIn('slow');	
				}
				
			}
		}
	}
}



function Querystring(qs) { // optionally pass a querystring to parse
	this.params = {};

	if (qs == null) qs = location.search.substring(1, location.search.length);
	if (qs.length == 0) return;

// Turn <plus> back to <space>
// See: http://www.w3.org/TR/REC-html40/interact/forms.html#h-17.13.4.1
	qs = qs.replace(/\+/g, ' ');
	var args = qs.split('&'); // parse out name/value pairs separated via &

// split out each name=value pair
	for (var i = 0; i < args.length; i++) {
		var pair = args[i].split('=');
		var name = decodeURIComponent(pair[0]);

		var value = (pair.length==2)
			? decodeURIComponent(pair[1])
			: name;

		this.params[name] = value;
	}
}

Querystring.prototype.get = function(key, default_) {
	var value = this.params[key];
	return (value != null) ? value : default_;
}

Querystring.prototype.contains = function(key) {
	var value = this.params[key];
	return (value != null);
}