function ajax_loadContent(where, url){
	AjaxRequest.get(
	  {
		'url': url
		,'onLoading':function() { document.getElementById(where).innerHTML = "<p style='text-align:center;'>Loading...</p>"; }
		,'onSuccess':function(req){ document.getElementById(where).innerHTML = req.responseText; }
	  }
	);
}
function ajax_addContent(where, url){
	AjaxRequest.get(
	  {
		'url': url
		,'onSuccess':function(req){ document.getElementById(where).innerHTML += req.responseText; }
	  }
	);
}


function AjaxRequest() {
	var req = new Object();
	req.timeout = null;
	req.generateUniqueUrl = true;
	req.url = window.location.href;
	req.method = "GET";
	req.async = true;
	req.username = null;
	req.password = null;
	req.parameters = new Object();
	req.requestIndex = AjaxRequest.numAjaxRequests++;
	req.responseReceived = false;
	req.groupName = null;
	req.queryString = "";
	req.responseText = null;
	req.responseXML = null;
	req.status = null;
	req.statusText = null;
	req.aborted = false;
	req.xmlHttpRequest = null;
	req.onTimeout = null; 
	req.onLoading = null;
	req.onLoaded = null;
	req.onInteractive = null;
	req.onComplete = null;
	req.onSuccess = null;
	req.onError = null;
	req.onGroupBegin = null;
	req.onGroupEnd = null;

	req.xmlHttpRequest = AjaxRequest.getXmlHttpRequest();
	if (req.xmlHttpRequest==null) { return null; }
	
	req.xmlHttpRequest.onreadystatechange = 
	function() {
		if (req==null || req.xmlHttpRequest==null) { return; }
		if (req.xmlHttpRequest.readyState==1) { req.onLoadingInternal(req); }
		if (req.xmlHttpRequest.readyState==2) { req.onLoadedInternal(req); }
		if (req.xmlHttpRequest.readyState==3) { req.onInteractiveInternal(req); }
		if (req.xmlHttpRequest.readyState==4) { req.onCompleteInternal(req); }
	};
	
	req.onLoadingInternalHandled = false;
	req.onLoadedInternalHandled = false;
	req.onInteractiveInternalHandled = false;
	req.onCompleteInternalHandled = false;
	req.onLoadingInternal = 
		function() {
			if (req.onLoadingInternalHandled) { return; }
			AjaxRequest.numActiveAjaxRequests++;
			if (AjaxRequest.numActiveAjaxRequests==1 && typeof(window['AjaxRequestBegin'])=="function") {
				AjaxRequestBegin();
			}
			if (req.groupName!=null) {
				if (typeof(AjaxRequest.numActiveAjaxGroupRequests[req.groupName])=="undefined") {
					AjaxRequest.numActiveAjaxGroupRequests[req.groupName] = 0;
				}
				AjaxRequest.numActiveAjaxGroupRequests[req.groupName]++;
				if (AjaxRequest.numActiveAjaxGroupRequests[req.groupName]==1 && typeof(req.onGroupBegin)=="function") {
					req.onGroupBegin(req.groupName);
				}
			}
			if (typeof(req.onLoading)=="function") {
				req.onLoading(req);
			}
			req.onLoadingInternalHandled = true;
		};
	req.onLoadedInternal = 
		function() {
			if (req.onLoadedInternalHandled) { return; }
			if (typeof(req.onLoaded)=="function") {
				req.onLoaded(req);
			}
			req.onLoadedInternalHandled = true;
		};
	req.onInteractiveInternal = 
		function() {
			if (req.onInteractiveInternalHandled) { return; }
			if (typeof(req.onInteractive)=="function") {
				req.onInteractive(req);
			}
			req.onInteractiveInternalHandled = true;
		};
	req.onCompleteInternal = 
		function() {
			if (req.onCompleteInternalHandled || req.aborted) { return; }
			req.onCompleteInternalHandled = true;
			AjaxRequest.numActiveAjaxRequests--;
			if (AjaxRequest.numActiveAjaxRequests==0 && typeof(window['AjaxRequestEnd'])=="function") {
				AjaxRequestEnd(req.groupName);
			}
			if (req.groupName!=null) {
				AjaxRequest.numActiveAjaxGroupRequests[req.groupName]--;
				if (AjaxRequest.numActiveAjaxGroupRequests[req.groupName]==0 && typeof(req.onGroupEnd)=="function") {
					req.onGroupEnd(req.groupName);
				}
			}
			req.responseReceived = true;
			req.status = req.xmlHttpRequest.status;
			req.statusText = req.xmlHttpRequest.statusText;
			req.responseText = req.xmlHttpRequest.responseText;
			req.responseXML = req.xmlHttpRequest.responseXML;
			if (typeof(req.onComplete)=="function") {
				req.onComplete(req);
			}
			if (req.xmlHttpRequest.status==200 && typeof(req.onSuccess)=="function") {
				req.onSuccess(req);
			}
			else if (typeof(req.onError)=="function") {
				req.onError(req);
			}

			// Clean up so IE doesn't leak memory
			delete req.xmlHttpRequest['onreadystatechange'];
			req.xmlHttpRequest = null;
		};
	req.onTimeoutInternal = 
		function() {
			if (req!=null && req.xmlHttpRequest!=null && !req.onCompleteInternalHandled) {
				req.aborted = true;
				req.xmlHttpRequest.abort();
				AjaxRequest.numActiveAjaxRequests--;
				if (AjaxRequest.numActiveAjaxRequests==0 && typeof(window['AjaxRequestEnd'])=="function") {
					AjaxRequestEnd(req.groupName);
				}
				if (req.groupName!=null) {
					AjaxRequest.numActiveAjaxGroupRequests[req.groupName]--;
					if (AjaxRequest.numActiveAjaxGroupRequests[req.groupName]==0 && typeof(req.onGroupEnd)=="function") {
						req.onGroupEnd(req.groupName);
					}
				}
				if (typeof(req.onTimeout)=="function") {
					req.onTimeout(req);
				}
			// Opera won't fire onreadystatechange after abort, but other browsers do. 
			// So we can't rely on the onreadystate function getting called. Clean up here!
			delete req.xmlHttpRequest['onreadystatechange'];
			req.xmlHttpRequest = null;
			}
		};

	req.process = 
		function() {
			if (req.xmlHttpRequest!=null) {
				// Some logic to get the real request URL
				if (req.generateUniqueUrl && req.method=="GET") {
					req.parameters["AjaxRequestUniqueId"] = new Date().getTime() + "" + req.requestIndex;
				}
				var content = null; // For POST requests, to hold query string
				for (var i in req.parameters) {
					if (req.queryString.length>0) { req.queryString += "&"; }
					req.queryString += encodeURIComponent(i) + "=" + encodeURIComponent(req.parameters[i]);
				}
				if (req.method=="GET") {
					if (req.queryString.length>0) {
						req.url += ((req.url.indexOf("?")>-1)?"&":"?") + req.queryString;
					}
				}
				req.xmlHttpRequest.open(req.method,req.url,req.async,req.username,req.password);
				if (req.method=="POST") {
					if (typeof(req.xmlHttpRequest.setRequestHeader)!="undefined") {
						req.xmlHttpRequest.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
					}
					content = req.queryString;
				}
				if (req.timeout>0) {
					setTimeout(req.onTimeoutInternal,req.timeout);
				}
				req.xmlHttpRequest.send(content);
			}
		};

	req.handleArguments = 
		function(args) {
			for (var i in args) {
				// If the AjaxRequest object doesn't have a property which was passed, treat it as a url parameter
				if (typeof(req[i])=="undefined") {
					req.parameters[i] = args[i];
				}
				else {
					req[i] = args[i];
				}
			}
		};

	req.getAllResponseHeaders =
		function() {
			if (req.xmlHttpRequest!=null) {
				if (req.responseReceived) {
					return req.xmlHttpRequest.getAllResponseHeaders();
				}
				alert("Cannot getAllResponseHeaders because a response has not yet been received");
			}
		};

	req.getResponseHeader =
		function(headerName) {
			if (req.xmlHttpRequest!=null) {
				if (req.responseReceived) {
					return req.xmlHttpRequest.getResponseHeader(headerName);
				}
				alert("Cannot getResponseHeader because a response has not yet been received");
			}
		};

	return req;
}

AjaxRequest.getXmlHttpRequest = function() {
	if (window.XMLHttpRequest) {
		return new XMLHttpRequest();
	}
	else if (window.ActiveXObject) {
		// Based on http://jibbering.com/2002/4/httprequest.html
		/*@cc_on @*/
		/*@if (@_jscript_version >= 5)
		try {
			return new ActiveXObject("Msxml2.XMLHTTP");
		} catch (e) {
			try {
				return new ActiveXObject("Microsoft.XMLHTTP");
			} catch (E) {
				return null;
			}
		}
		@end @*/
	}
	else {
		return null;
	}
};


AjaxRequest.isActive = function() {
	return (AjaxRequest.numActiveAjaxRequests>0);
};

AjaxRequest.get = function(args) {
	AjaxRequest.doRequest("GET",args);
};

AjaxRequest.post = function(args) {
	AjaxRequest.doRequest("POST",args);
};

AjaxRequest.doRequest = function(method,args) {
	if (typeof(args)!="undefined" && args!=null) {
		var myRequest = new AjaxRequest();
		myRequest.method = method;
		myRequest.handleArguments(args);
		myRequest.process();
	}
}	;

AjaxRequest.submit = function(theform, args) {
	var myRequest = new AjaxRequest();
	if (myRequest==null) { return false; }
	var serializedForm = AjaxRequest.serializeForm(theform);
	myRequest.method = theform.method.toUpperCase();
	myRequest.url = theform.action;
	myRequest.handleArguments(args);
	myRequest.queryString = serializedForm;
	myRequest.process();
	return true;
};

AjaxRequest.serializeForm = function(theform) {
	var els = theform.elements;
	var len = els.length;
	var queryString = "";
	this.addField = 
		function(name,value) { 
			if (queryString.length>0) { 
				queryString += "&";
			}
			queryString += encodeURIComponent(name) + "=" + encodeURIComponent(value);
		};
	for (var i=0; i<len; i++) {
		var el = els[i];
		if (!el.disabled) {
			switch(el.type) {
				case 'text': case 'password': case 'hidden': case 'textarea': 
					this.addField(el.name,el.value);
					break;
				case 'select-one':
					if (el.selectedIndex>=0) {
						this.addField(el.name,el.options[el.selectedIndex].value);
					}
					break;
				case 'select-multiple':
					for (var j=0; j<el.options.length; j++) {
						if (el.options[j].selected) {
							this.addField(el.name,el.options[j].value);
						}
					}
					break;
				case 'checkbox': case 'radio':
					if (el.checked) {
						this.addField(el.name,el.value);
					}
					break;
			}
		}
	}
	return queryString;
};


AjaxRequest.numActiveAjaxRequests = 0;
AjaxRequest.numActiveAjaxGroupRequests = new Object();
AjaxRequest.numAjaxRequests = 0;