var xmlhttp;  
            try {
               xmlhttp = new XMLHttpRequest();
            } catch (e) {
               try {
                  xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
               } catch (e) {
                   try {
                     xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
                  } catch (e) {
                     alert("Something went wrong");
                     return false;
                  }
               }
            }