var xmlHttp;

function callAjax(params,mode)
{ 
	xmlHttp=GetXmlHttpObject();
	if (xmlHttp==null)
	 {
		 alert ("Browser does not support HTTP Request");
		 return;
	 }
	switch(mode){ 
		case "nletter":
			var url="nletter_register.php";
			url=url+"?email="+params;
			xmlHttp.onreadystatechange=stateChanged;
			xmlHttp.open("GET",url,true);
			xmlHttp.send(null);
		break;
		}
}

function stateChanged() 
{ 
	if (xmlHttp.readyState==4 || xmlHttp.readyState=="Success")
	 { 
	 	alert('Thank you ')
	 } 
}
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;
}