function GetXmlHttpObject()
{
	var xmlHttp = null;
	
	try
	{
		// Firefox, Opera 8.0+, Safari
		xmlHttp = new XMLHttpRequest();
	}
	catch (e)
	{
		// Internet Explorer
		try
		{
			xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
		}
		catch (e)
		{
			xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
		}
	}
	
	return xmlHttp;
}

function send_request(url, callback)
{
	var now = new Date();
	var timestamp = now.getTime().toString().substring(0,10);
	
	if (http == null)
	{
		alert("Browser does not support HTTP Request")
		return;
	}
	
	http.open("POST", url, true);
	
	http.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
	http.setRequestHeader("Content-length", timestamp.length);
	http.setRequestHeader("Connection", "close");
	
	//http.onreadystatechange = callback;
	http.onreadystatechange = function()
	{
		if(http.readyState == 4 && http.status == 200)
		{
			callback();
		}
	}
	http.send(timestamp);
}