function Ajax()
{
	this.req = null;
	this.url = null;
	this.status = null;
	this.statusText = '';
	this.method = 'GET';
	this.async = true;
	this.dataPayload = null;
	this.readyState = null;
	this.responseText = null;
	this.responseXML = null;
	this.handleResp = null;
	this.responseFormat = 'text'; // 'text', 'xml', 'object'
	this.mimeType = null;
	this.headers = [];

	this.init = function()
	{
		var i = 0;
		var reqTry = [
		function() { return new XMLHttpRequest(); },
		function() { return new ActiveXObject('Msxml2.XMLHTTP') },
		function() { return new ActiveXObject('Microsoft.XMLHTTP' )} ];

		while (!this.req && (i < reqTry.length))
		{
			try
			{
				this.req = reqTry[i++]();
			}
			catch(e) {}
		}
		return true;
	};
	this.doGet = function(url, hand, format)
	{
		this.url = url;
		this.handleResp = hand;
		this.responseFormat = format || 'text';
		this.doReq();
	};
	this.doPost = function(url, dataPayload, hand, format)
	{
		this.url = url;
		this.dataPayload = dataPayload;
		this.handleResp = hand;
		this.responseFormat = format || 'text';
		this.method = 'POST';
		this.doReq();
	};
	this.doReq = function()
	{
		var self = null;
		var req = null;
		var headArr = [];

		if (!this.init())
		{
			alert('Could not create XMLHttpRequest object.');
			return;
		}
		req = this.req;
		req.open(this.method, this.url, this.async);
		if (this.method == "POST")
		{
			this.req.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
		}
		if (this.method == 'POST')
		{
			req.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
		}
		self = this;
		req.onreadystatechange = function()
		{
			var resp = null;
			self.readyState = req.readyState;
			if (req.readyState == 4)
			{
				self.status = req.status;
				self.statusText = req.statusText;
				self.responseText = req.responseText;
				self.responseXML = req.responseXML;

				switch(self.responseFormat)
				{
					case 'text':
						resp = self.responseText;
						break;
					case 'xml':
						resp = self.responseXML;
						break;
					case 'object':
						resp = req;
						break;
				}

				if (self.status > 199 && self.status < 300)
				{
					if (!self.handleResp)
					{
						alert('No response handler defined for this XMLHttpRequest object.');
						return;
					}
					else
					{
						self.handleResp(resp);
					}
				}

				else
				{
					self.handleErr(resp);
				}
			}
		}
		req.send(this.dataPayload);
	};

	this.abort = function()
	{
		if (this.req)
		{
			this.req.onreadystatechange = function() { };
			this.req.abort();
			this.req = null;
		}
	};
	this.handleErr = function()
	{
		var errorWin;
		// Create new window and display error
		try
		{
			errorWin = window.open('', 'errorWin');
			errorWin.document.body.innerHTML = this.responseText;
		}
		// If pop-up gets blocked, inform user
		catch(e)
		{
			alert('An error occurred, but the error message cannot be' +
			' displayed because of your browser\'s pop-up blocker.\n' +
			'Please allow pop-ups from this Web site.');
		}
	};
	this.setMimeType = function(mimeType)
	{
		this.mimeType = mimeType;
	};
	this.setHandlerResp = function(funcRef)
	{
		this.handleResp = funcRef;
	};
	this.setHandlerErr = function(funcRef)
	{
		this.handleErr = funcRef;
	};
	this.setHandlerBoth = function(funcRef)
	{
		this.handleResp = funcRef;
		this.handleErr = funcRef;
	};
	this.setRequestHeader = function(headerName, headerValue)
	{
		this.headers.push(headerName + ': ' + headerValue);
	};
}