var xmlHttp

function checkEmailAddress(str) { 
	xmlHttp=GetXmlHttpObject();
	if (xmlHttp==null)
	{
		alert ("Your browser does not support AJAX!");
		return;
  	} 
	var url="ajax_checkemailaddress.asp?u="+str+"&sid="+Math.random();
	xmlHttp.onreadystatechange=stateChanged;
	xmlHttp.open("GET",url,true);
	xmlHttp.send(null);
}


function stateChanged() { 
	if (xmlHttp.readyState==4)
	{
		document.getElementById("txtHint").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;
}