function getXMLHttpRequest()
{
	var XHR = null;
	var browserUtente = navigator.userAgent.toUpperCase();
	
	if(typeof(XMLHttpRequest) === "function" || typeof(XMLHttpRequest) === "object")
		XHR = new XMLHttpRequest();
	else if(window.ActiveXObject && browserUtente.indexOf("MSIE 4") < 0)
	{
		if(browserUtente.indexOf("MSIE 5") < 0)
			XHR = new ActiveXObject("Msxml2.XMLHTTP");
		else
			XHR = new ActiveXObject("Microsoft.XMLHTTP");
	}

	return XHR;
}