title: Opening an undefined URL with xmlHttp Request
body: <p>I'm making a server request like this:</p>
  
  <pre><code>    //document.write("getmessages.php?q="+employeee);
      xmlHttp.open("GET","../ajax/getmessages.php?q="+employeee,true);
  
      // define the method to handle server responses
      xmlHttp.onreadystatechange = handleServerResponse;
      // make the server request
      xmlHttp.send(null);
  </code></pre>
  
  <p>The code works fine, but its trying to make a popup, which if I open it, comes up with: </p>
  
  <pre><code>The requested URL /undefined was not found on this server.
  
  Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.
  </code></pre>
  
  <p>I'm not sure what's causing this error</p>