title: how to clear the cache data when using ajax?
body: <p>I am using Ajax to retrieve the data from server as below based on some ID to perform auto suggest function. however when i submit the form and update the database, the auto suggest field suppose should not contain anything for this ID anymore, but it will still retrieve data from its cache. do anyone know how to clear the cache and make the Ajax sending request to get the latest data from server every time i press the button? Pls help i really stuck on this whole weeks and couldnt find the solution.</p>
  
  <p>For example: when ID field is 00001, auto suggest field will be 1,2,3. After i submit the form and update the database, when i search for 00001 again, it should not contain anything but it does, it still cache the data as 1,2,3 in suggest field...</p>
  
  <pre><code>if (window.XMLHttpRequest)
  {// code for IE7+, Firefox, Chrome, Opera, Safari
   xmlhttp=new XMLHttpRequest();
  }
  else
   {// code for IE6, IE5
  xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
  }
  xmlhttp.onreadystatechange=function()
  {
  if (xmlhttp.readyState==4 &amp;&amp; xmlhttp.status==200)
    {
  var data=xmlhttp.responseText;
  alert(data);
  
  }
  }
  xmlhttp.open("GET","gethint.php?q="+str,true);
  xmlhttp.send();
  </code></pre>