<script>
function showUser(str)
{
if (str=='')
  {
  document.getElementById('txtHint').innerHTML='';
  return;
  }
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 && xmlhttp.status==200)
    {
    document.getElementById('txtHint').innerHTML=xmlhttp.responseText;
    }
  }
xmlhttp.open('GET','************************='+str,true);
xmlhttp.send();
}
</script>