var request = null;
   function createRequest() {
 
try 
	 {
       request = new XMLHttpRequest();
     } 
	 catch (trymicrosoft) 
	 {
       try 
	   {
         request = new ActiveXObject("Msxml2.XMLHTTP");
       } 
	   catch (othermicrosoft) 
	   {
         try 
		 {
           request = new ActiveXObject("Microsoft.XMLHTTP");
         }
		 catch (failed) 
		 {
           request = null;
         }
       }
	   
     }

     if (request == null)
       alert("Error creating request object!");
   }