function callAjax(url, pageElement, callMessage, errorMessage) {  

    document.getElementById(pageElement).innerHTML = callMessage;  

    try {  

    req = new XMLHttpRequest(); /* e.g. Firefox */  

    } catch(e) {  

      try {  

      req = new ActiveXObject("Msxml2.XMLHTTP");  /* some versions IE */  

      } catch (e) {  

        try {  

        req = new ActiveXObject("Microsoft.XMLHTTP");  /* some versions IE */  

        } catch (E) {  

         req = false;  

        }  

      }  

    }  

    req.onreadystatechange = function() {responseAjax(pageElement, errorMessage);};  

    req.open("GET",url,true);  

    req.send(null);  

 }  

  

function responseAjax(pageElement, errorMessage) {  

  var output = '';  

  if(req.readyState == 4) {  

     if(req.status == 200) {  

        output = req.responseText;  

        document.getElementById(pageElement).innerHTML = output;  

        } else {  

        document.getElementById(pageElement).innerHTML = errorMessage+"\n"+output;  

        }  

     }  

 }