function ajax() 
{
	this.exists = true;
	this.req = null;
	this.url = null;
	this.method = null;
	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 = 'xml';
	this.mimeType = null;
	this.init = function() 
	{
		if (!this.req)
		{
			try 
			{
				this.req = new XMLHttpRequest();
			}
			catch (e) 
			{
				try 
				{
					this.req = new ActiveXObject('MSXML2.XMLHTTP');
				}
				catch (e) 
				{
					try 
					{
						this.req = new ActiveXObject('Microsoft.XMLHTTP');
					}
					catch (e) 
					{
						return false;
					}
				}
			}
		}
		
		return this.req;
	}
	this.doReq = function() 
	{
		var self = this; // Fix loss-of-scope in inner function.
		if (!this.init) 
		{
			alert('Could not create XMLHttpRequest object.');
			return;
		}
		if (this.mimeType) 
		{
			try 
			{
				this.req.overrideMimeType(this.mimeType);
			}
			catch (e) 
			{
				// couldn't override MIME type -- IE6 or Opera?
			}
		}
		/* If the current browser is not IE, define the onreadystate change function before sending the request. */
		if (!document.all) 
			{
			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);
					}
				}
			}
		}
		if (this.method == "POST") 
		{
			this.req.open(this.method,this.url,this.async);
			if (this.postData == null) 
			{
				this.postData = 'null=null';
			}
			this.req.setRequestHeader('Content-type', 'application/x-www-form-urlencoded; charset=iso-8859-1');
			this.req.setRequestHeader('Content-length', this.postData.length);
			this.req.setRequestHeader('Connection', 'close');
			this.req.send(this.postData);
		}
		else if (this.method == "GET") 
		{
			if (this.postData != null)
			{
				this.url += '?';
				this.url += this.postData;
			}
			this.req.open(this.method,this.url,this.async);
			this.req.send(null);
		}
		/* If the current browser is IE, define the onreadystate change function after sending the request. */
		if (document.all) 
			{
			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.setMimeType = function(mimeType) 
	{
		this.mimeType = mimeType;
	}
	this.handleErr = function() 
	{
		var errorWin;
		try 
		{
			errorWin = window.open('', 'errorWin');
			errorWin.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.abort = function() 
	{
		if (this.req) 
		{
			this.req.onreadystatechange = function() { };
			this.req.abort();
			this.req = null;
			alert("ABORT");
		}
	}
	this.doGet = function(url, hand, format, newPostData) 
	{
		if (!this.req) 
		{
			this.init();
		}
		this.url = url;
		this.handleResp = hand;
		this.responseFormat = format || 'text';
		this.postData = newPostData || null;
		this.doReq();
		
	}
}