var xmlHttp = createXmlHttpRequestObject()

function createXmlHttpRequestObject()
{
	var xmlHttp;
	try
	{
		xmlHttp = new XMLHttpRequest();
	}
	catch(e)
	{
		var XmlHttpVersions = new Array("MSXML2.XMLHTTP.6.0", "MSXML2.XMLHTTP.5.0", "MSXML2.XMLHTTP.4.0", "MSXML2.XMLHTTP.3.0", "MSXML2.XMLHTTP", "Microsoft.XMLHTTP");
		for(var i=0; i < XmlHttpVersions.length && !xmlHttp; i++)
		{
			try
			{
				xmlHttp = new ActiveXObject(XmlHttpVersions[i]);
			}
			catch(e)
			{
			}
		}
	}
	if(!xmlHttp)
	{
		alert("Błąd podczas tworzenia obiektu XMLHttpRequest.");
	}
	else
	{
		return xmlHttp;
	}
}