[Ajax] setInterval

<script type="text/javascript">
setInterval("sendRequest()",1000)
function createRequestObject() 
{
   var req;

   if(window.XMLHttpRequest)
   {
      req = new XMLHttpRequest();
   } 
   else if(window.ActiveXObject) 
   {
      req = new ActiveXObject("Microsoft.XMLHTTP");
   }
   else 
   {
      alert('Fail');
   }

   return req;

}

var http = createRequestObject(); 
function sendRequest() 
{
   http.open('get', 'test3.php?uid='+<?php print $_SESSION['userid']; ?>);
   http.onreadystatechange = handleResponse;
   http.send(null);
} 

function handleResponse()
{

   if(http.readyState == 4 && http.status == 200)
   {
      if(http.responseText)
      {
         document.getElementById("resultaat").innerHTML = http.responseText; 
      }
   }
}

<script type="text/javascript">
setInterval("sendRequest()",1000)
function createRequestObject() 
{
   var req;
 
   if(window.XMLHttpRequest)
   {
      req = new XMLHttpRequest();
   } 
   else if(window.ActiveXObject) 
   {
      req = new ActiveXObject("Microsoft.XMLHTTP");
   }
   else 
   {
      alert('Fail');
   }
 
   return req;
 
}
 
var http = createRequestObject(); 
function sendRequest() 
{
   http.open('get', 'test3.php?uid='+<?php print $_SESSION['userid']; ?>);
   http.onreadystatechange = handleResponse;
   http.send(null);
} 
 
function handleResponse()
{
 
   if(http.readyState == 4 && http.status == 200)
   {
      if(http.responseText)
      {
         document.getElementById("resultaat").innerHTML = http.responseText; 
      }
   }
}