// JavaScript Document
var xmlHttp

function check_user_name(form)
{
	get_user_name_status(form.TR_user_name.value);
	//document.getElementById("check_user_name_status").innerHTML = "<img src='../images/loading.gif'>";
	document.getElementById("check_user_name_status").innerHTML = "Checking....";
}

function get_user_name_status(user_name)
{ 
	xmlHttp=GetXmlHttpObject()
	if (xmlHttp==null)
	{
		alert ("Browser does not support HTTP Request")
		return
	}
	var url="check_user_name.php"
	url=url+"?user_name="+user_name
	xmlHttp.onreadystatechange=stateChanged 
	xmlHttp.open("GET",url,true)
	xmlHttp.send(null)
}

function stateChanged() 
{
	if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete")
		document.getElementById("check_user_name_status").innerHTML=xmlHttp.responseText 
}

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