I am trying to append a timestamp to my URL which is called by AJAX every 5 seconds. I am doing this to stop caching in Internet Explorer browsers. However the AJAX call appears to be not calling now but there are no errors....

This code works

<script>
  function loaddoc()
  {
   var xmlhttp=new XMLHttpRequest();
   xmlhttp.onreadystatechange=function(){
    if (xmlhttp.readyState==4 && xmlhttp.status==200) {
     document.getElementById("trainblock").innerHTML=xmlhttp.responseText;
    } 
   }
   xmlhttp.open("GET","networkgettrainsleicester.php",true);
   xmlhttp.send();
  }
 </script>

With the extra code to append the timestamp does not work

 <script>
  function loaddoc()
  {
   var xmlhttp=new XMLHttpRequest();
   xmlhttp.onreadystatechange=function(){
    if (xmlhttp.readyState==4 && xmlhttp.status==200) {
     document.getElementById("trainblock").innerHTML=xmlhttp.responseText;
    } 
   }
   d=new Date();
   xmlhttp.open("GET","networkgettrainsleicester.php+'?'+d.getTime()",true);
   xmlhttp.send();
  }
 </script>

Any help appreciated Thanks