var subHttp

function showHint(str)
{ 
if (str.length==0)
  { 
  //alert("hello");
  document.getElementById("username").innerHTML=""
  return
  }
subHttp=GetXmlHttpObject()
if (subHttp==null)
  {
  alert ("Browser does not support HTTP Request")
  return
  } 
var url="get_username.php"
url=url+"?var="+str
subHttp.onreadystatechange=stateChanged 
subHttp.open("GET",url,true)
subHttp.send(null)

} 

function stateChanged() 
{ 
if (subHttp.readyState==4 || subHttp.readyState=="complete")
 { //alert(subHttp.responseText);
 document.getElementById("con_name").innerHTML=subHttp.responseText 

} 
}


function GetXmlHttpObject()
{
var subHttp=null;
try
 {
 // Firefox, Opera 8.0+, Safari
 subHttp=new XMLHttpRequest();
 }
catch (e)
 {
 // Internet Explorer
 try
  {
  subHttp=new ActiveXObject("Msxml2.XMLHTTP");
  }
 catch (e)
  {
  subHttp=new ActiveXObject("Microsoft.XMLHTTP");
  }
 }
return subHttp;
}