var xmlhttp = new_http_object();//(window.XMLHttpRequest ? new XMLHttpRequest(): ((window.ActiveXObject) ? new ActiveXObject("Microsoft.XMLHTTP") : null) );
var target_msg_id = "";
function new_http_object(){
	var xmlobj = null;
	// try to instantiate the native XMLHttpRequest object
	try{// create an XMLHttpRequest object
		xmlobj = new XMLHttpRequest();
	}
	catch(e){// assume IE6 or older
		try{
			xmlobj = new ActiveXObject("Microsoft.XMLHttp");
		}
		catch(e){ }
	}
	// return the created object or display an error message
//	if (!xmlHttp)
//		alert("Error creating the XMLHttpRequest object.");
//	else
	return xmlobj;
}

function renew_session(){
		target_msg_id = 'renew_message_tag';
		if(renew_by_ajax()){
			setTimeout("renew_session()", 150000);
			return false;
		}
	//	alert('not renewed');
		setTimeout("renew_session()", 150000);
	return false;
}

/*
function renew_from_server(){
	return_value = renew_by_ajax();
	id_list = return_value.split(",");
	if(id_list[0] == 'ok'){
		return true;
	}
	else{
		return false;
	}
}

*/
function renew_by_ajax(){	
	if (this.xmlhttp){
		try{

		this.xmlhttp.open("POST",'./renewsession.php',true);
		this.xmlhttp.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
		this.xmlhttp.onreadystatechange=process_renew;

		var send_val = '&ok=ok';
		//alert(send_val);	
		this.xmlhttp.send(send_val);
		}
		catch(e){
			return false;
		}
	return true;
	}
	return false;	
}

function finish_renew(return_value){
	try{
		id_list = return_value.split(",");
		if(id_list[0] == 'ok'){
//			var curr_time = new Date();
//			document.getElementById(target_msg_id).innerHTML  = "Sessions Renewed at " + curr_time.getHours() + ":" + curr_time.getMinutes();
//			alert('Session Renewed');
		}
	}
	catch(e){
	}
}

function process_renew(){
	if (xmlhttp.readyState == 4){
		if (xmlhttp.status == 200){
			try{
				//alert(xmlhttp.responseText);
				finish_renew(xmlhttp.responseText);
			}
			catch(e){
			}
		}
	}
}