function GetXmlHttpRequest() {
   if (window.XMLHttpRequest) {
     return new XMLHttpRequest();
   } else if (window.ActiveXObject) {
     var progIDs = [ 'Msxml2.XMLHTTP', 'Microsoft.XMLHTTP' ];
 
     for (var i = 0; i < progIDs.length; i++) {
        try {
          var xmlHttp = new ActiveXObject(progIDs[i]);
          return xmlHttp;
        }
        catch (ex) {
        }
     }     
   } else {     
     return null;
   }
 }
 
 function UpdateLastRequest() {
	 var ORequest = GetXmlHttpRequest();
	 if (ORequest != null) {			
			ORequest.open("GET", "/section/user/common/updatelastrequest.aspx", true);
			ORequest.send(null);
	 }	 
	 setTimeout(UpdateLastRequest, 900000);
 }