function Ajax() {
 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;
 this.setMimeType = function(mimeType) {
		this.mimeType = mimeType;
 };
 this.setHandlerErr = function(funcRef) {
	this.handleErr = funcRef;  
 }
 this.setHandlerBoth = function(funcRef) {
	 this.handleResp = funcRef;
	 this.handleErr = funcRef;
 };
 this.init = function() {
		 if (!this.req) {
		   try {
			 // Try to create object for Firefox, Safari, IE7, etc.
			 this.req = new XMLHttpRequest();
		   }
		   catch (e) {
			 try {
			   // Try to create object for later versions of IE.
			   this.req = new ActiveXObject('MSXML2.XMLHTTP');
			 }
			 catch (e) {
			   try {
				 // Try to create object for early versions of IE.
				 this.req = new ActiveXObject('Microsoft.XMLHTTP');
			   }
			   catch (e) {
				 // Could not create an XMLHttpRequest object.
				 return false;
			   }
			 }
		   }
		 }
		 return this.req;
	 };
  this.doReq = function() {
		 if (!this.init()) {
		   alert('Could not create XMLHttpRequest object.');
		   return;
		 }
		 this.req.open(this.method, this.url, this.async);
		 if (this.mimeType) {
			 try {
			   this.req.overrideMimeType(this.mimeType);
			 }
			 catch (e) {
			   // couldn't override MIME type  --  IE6 or Opera?
			 }
		 } 
		 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.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
		if (this.postData)
		{
			this.req.setRequestHeader("Content-length", this.postData.length);
		}
		this.req.setRequestHeader("Connection", "close");
		this.req.send(this.postData);
	 };
  
	this.handleErr = function() {
		 var errorWin;
		 try {
		   errorWin = window.open('', 'errorWin');
		   errorWin.document.body.innerHTML = this.responseText;
		 }
		 catch (e) {
		   alert('An error occurred, 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 web site if you want to '
			 + 'see the full error messages.\n'
			 + '\n'
			 + 'Status Code: ' + this.req.status + '\n'
			 + 'Status Description: ' + this.req.statusText);
		 }
	};
	this.doGet = function(url, hand, format) {
		 this.url = url;
		 this.handleResp = hand;
		 this.responseFormat = format || 'text';
		 this.doReq();
	};
}