function createRequest() {
   try {
      request = new XMLHttpRequest();
      }
   catch (tryMS) {
      try {
         request = new ActiveXObject("Msxml2.XMLHTTP");
         }
      catch (otherMS) {
         try {
            request = new ActiveXObject("Microsoft.XMLHTTP");
            }
         catch (failed) {
            request = null;
            }
         }
      }
   return request;
   }