function start() {
		starttime = (new Date()).getTime();	
}

function leave(purl, activity) {
		stoptime = (new Date()).getTime();
		spendtime = Math.round((stoptime-starttime)/1000);
		var myRequest = new Request({url: '../purl_timer.php'});
		myRequest.send('spent='+spendtime+'&purl='+purl+'&activity='+activity);
		//alert(purl);
		//alert(spendtime);
}