function Ajax() {
	//////// Declare Class variables
	this.req = null;
	this.url = null;
	this.method = 'GET';
	this.async = true;
	this.status = null;
	this.statusText = '';
	this.postData = null;
	this.readyState = null;
	this.responseText = null;
	this.responseXML = null;
	this.handleResp = null;
	this.responseFormat = 'text';  // text, xml, or object
	this.mimeType = null;
	
	/////// Declare Class functions
	this.init = function() {
		if (!this.req) {
			try {
				// Mozilla, Safari, IE7
				this.req = new XMLHttpRequest();
			} catch (e) {
				try {
					// Later IE Versions
					this.req = new ActiveXObject('MSXML2.XMLHTTP');
				} catch (e) {
					try {
						// Early IE versions
						this.req = new ActiveXObject('Microsoft.XMLHTTP');
					}
					catch (e) {
						// Fail	
						return false;
					}
				}
			}
		}	// end if
		return this.req;
	};
	///////
	this.doReq = function () {
		if (!this.init()) {
			alert('Could not create XMLHttpRequest ojbect.');
			return;
		}
		this.req.open(this.method, this.url, this.async);
		if (this.method == "POST") {
			this.req.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
		}
		if (this.mimeType) {
			try {
				req.overrideMimeType(this.mimeType);
			} catch (e) {
				// Can't override MimeType
			}
		}
		var self = this; // Fix loss-of-scope in inner function
		this.req.onreadystatechange = function() {
			var resp = null;
			if (self.req.readyState == 4) {
				switch (self.responseFormat) {
					case 'text':
						resp = self.req.responseText;
						break;
					case 'xml':
						resp = self.req.responseXML;
						break;
					case 'object':
						resp = req;
						break;
				}
				if (self.req.status >= 200 && self.req.status <=299) {
					self.handleResp(resp);
				} else {
					self.handleErr(resp);
				}
			}
		};
		this.req.send(this.postData);
	};
	/////////
	this.setMimeType = function(mimeType) {
		this.mimeType = mimeType;
	};
	/////////
	this.handleErr = function() {
		var errorWin;
		try {
			errorWin = window.open('','errorWin');
			errorWin.document.body.innerHTML = 'this.responseText';
		} catch (e) {
			alert ('An error occured, but the error message cannot be '
				+ 'displayed. This is probably because of your browser\'s '
				+ 'pop-up blocker. \n'
				+ 'Please allow pop-ups from this webs site if you want to '
				+ 'see the full error messages.\n'
				+ '\n'
				+ 'Status Code: ' + this.req.status + '\n'
				+ 'Status Description: ' + this.req.statusText);
		}
	};
	/////////
	this.setHandlerBoth = function(funcRef) {
		this.handleResp = funcRef;
		this.handleErr = funcRef;
	};
	/////////
	this.abort = function() {
		if (this.req) {
			this.req.onreadystatechange = function() { };
			this.req.abort();
			this.req = null;
		}
	};
	//////////
	this.doGet = function(url, hand, format) {
		this.url = url;
		this.handleResp = hand;
		this.responseFormat = format || 'text';
		this.doReq();
	};
	//////////
	this.doPost = function(url, postData, hand, format) {
		this.url = url;
		this.handleResp = hand;
		this.responseFormat = format || 'text';
		this.method = 'POST';
		this.postData = postData;
		this.doReq();
	};

} // end of class