xmlHttp = getXmlHttpObject();

function getXmlHttpObject() 
{
         var xmlHttp = false;
         try {
	     xmlHttp = new XMLHttpRequest();
         }
	 catch(e) {
             var XmlHttpVersions = new Array("MSXML2.XMLHTTP.7.0",
                                             "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){}
	     }
	 }

         return xmlHttp;
}