title: update variable after success of ajax function
body: <p>Hey guys quick question, I am sending a request with the jquery ajax function with a variable. After the request I want that variable updated to match the value of the sent back information, so next time the ajax function executes, it send the value of the new variable.<br>
  <strong>EDIT</strong></p>
  
  <pre><code>$(document).ready(function()
  {
  var countusers='&lt;?php echo $countusers; ?&gt;';
  
  function refresh() {
  
   $.ajax({
     type: "POST",
     data: "action=refresh_topic&amp;countusers=" + countusers,
     url: "tester.php",
      dataType: 'json',
     success: function(json)
     {
      var countusers=json.countusers;
   }
  })
  }
  setInterval(refresh, 3000);
  
      });
  </code></pre>