var request = false;
var elapsed = new Date().getTime();
setTimeout('sendRequest()', 1000*600);

function getRequestObject()
{
	var req = false;
	if(window.XMLHttpRequest) 
	{
  		try { req = new XMLHttpRequest();} 
  		catch(e) {}
	} 
	else if(window.ActiveXObject) 
	{
       		try { req = new ActiveXObject("Msxml2.XMLHTTP"); } 
		catch(e)
		{
			try { req = new ActiveXObject("Microsoft.XMLHTTP"); } 
			catch(e) {}  		
		}
   	}

	return req;
}


function sendRequest()
{ 
	var t = new Date().getTime();
	request = getRequestObject();
 	request.onreadystatechange = processResponse;
	request.open("POST", '/store/sessionstate.php');
 	request.setRequestHeader('Content-Type','application/x-www-form-urlencoded');
  	request.send('t=' + t);
}

function processResponse()
{
	if (request.readyState == 4 && request.status == 200) 
	{
		if(request.responseText == '0')
		{
			var current_time = new Date().getTime();
			if((current_time-elapsed)/(1000*3600) < 12)
				setTimeout('sendRequest()', 1000*600);
		}
	}
	
}