function GetHTTPObject()
{   
	if (window.ActiveXObject)  
		return new ActiveXObject("Microsoft.XMLHTTP");  
	else if (window.XMLHttpRequest)     
		return new XMLHttpRequest();
	else 
		return null;   
}

function CallAjax(url, callback)
{        
	var http = GetHTTPObject();    
	if (http != null) 
	{
		if (url.indexOf("?") > -1)
			url += "&dummy=" + CreateDummy();
		else
			url += "?dummy=" + CreateDummy();
		http.open("GET", url, true);
		http.send(null);
		http.onreadystatechange = function()
		{ 
			if(http.readyState == 4)
			{
				responseText = http.responseText;
				eval(callback); 
			}
		};   
	}
}

function CreateDummy()
{
	var dummy = Math.random();
	dummy = dummy.toString().substr(2);
	return dummy;
}