function InitAjax(){
         var ajax = false;
  
         if(window.XMLHttpRequest) { 
                 ajax = new XMLHttpRequest();
                 if (ajax.overrideMimeType) {
                         ajax.overrideMimeType("text/xml");
                 }
         }
         else if (window.ActiveXObject) {
                 try 
                 {
                         ajax = new ActiveXObject("Msxml2.XMLHTTP");
                 } 
                 catch (e) 
                 {
                         try 
                         {
                                 ajax = new ActiveXObject("Microsoft.XMLHTTP");
                         } 
                         catch (e) 
                         {}
                 }
         }
         if (!ajax) 
         {
                 window.alert("Can not create XMLHttpRequest object instance.");
                 return false;
         }
         else
         {
            return ajax;
         }


}