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";
	this.mimeType = null;


	this.init = function() {
		var i = 0;
		var reqTry = [
		  function() { return new XMLHttpRequest(); },// Firefox, Safari, IE7, etc
		  function() { return new ActiveXObject('Msxml2.XMLHTTP') }, // IE6
		  function() { return new ActiveXObject('Microsoft.XMLHTTP' )} ]; // Older

		while (!this.req && (i < reqTry.length)) {
		  try {
		    this.req = reqTry[i++]();
		  }
		  catch(e) {}
		}
		return true;
	};

	this.doReq = function() {
		if (!this.init()) {
			alert("Could not create XMLHttpRequest object.");
			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) {
				// couldn't override MIME type -- funny browser like IE6 or Opera?
			}
		}*/
		var self = this // Inner function loss-of-scope work-around
		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 = self.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 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.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();
	}
}