var req1;
function createXHR()
{
    var xhr;
    try{
        xhr = new ActiveXObject("Msxml2.XMLHTTP");
    }catch (e) {
       try{
            xhr = new ActiveXObject("Microsoft.XMLHTTP");
        }catch (E)  {
            xhr = false;
        }
    }

    if (!xhr && typeof XMLHttpRequest != 'undefined'){
        xhr = new XMLHttpRequest();
    }

    return xhr;
}
	function GetXmlHttpObject(){
		if (window.XMLHttpRequest)
		  {
		  // code for IE7+, Firefox, Chrome, Opera, Safari
		  return new XMLHttpRequest();
		  }
		if (window.ActiveXObject)
		  {
		  // code for IE6, IE5
		  return new ActiveXObject("Microsoft.XMLHTTP");
		  }
		return null;
	}


 function validateUserName(requestSource){
      var url = null;
      var userName = document.getElementById("userNameId").value;
      req1 = new createXHR();
      if(requestSource=='operation'){
         url = "operation?action=validateUserName&userName="+userName;
      }else{
         url = "scm?action=validateUserName&userName="+userName;
      }  
      req1.open('POST', url, true);
      req1.onreadystatechange = checkAvailability;
      req1.send(null);
 }

function checkAvailability(){
  if(req1.readyState==4 && req1.status==200){
       var outputdata= req1.responseText;
       var mdiv = document.getElementById("userIdMessage");
       mdiv.innerHTML = outputdata;
       document.getElementById("userIdMessage").value=outputdata;
       setTimeout('messageDisplay()', 4000);
     }
  }

  function messageDisplay(){
      var outputdata= '';
      var mdiv = document.getElementById("userIdMessage");
      mdiv.innerHTML = outputdata;
      document.getElementById("userIdMessage").value=outputdata;
  }