function createXmlHttpRequestObject() 
{ 
// will store the reference to the XMLHttpRequest object 

 var xmlHttp; 
// if running Internet Explorer 
   if(window.ActiveXObject) 
   { 
     try 
     { 
       xmlHttp = new ActiveXObject("Microsoft.XMLHTTP"); 
     } 
     catch (e) 
     { 
       xmlHttp = false; 
     } 
   } 
   // if running Mozilla or other browsers 
   else 
   { 
     try 
     { 
       xmlHttp = new XMLHttpRequest(); 
       
     } 
     catch (e) 
     { 
       xmlHttp = false; 
     } 
   }  
   // return the created object or display an error message 
   if (!xmlHttp) 
     alert("Error creating the XMLHttpRequest object."); 
   else 
     return xmlHttp; 
} 
var http=createXmlHttpRequestObject();