if (window.addEventListener)
	 window.addEventListener("load", check_render_time, false) //invoke function
	else if (window.attachEvent)
	 window.attachEvent("onload", check_render_time) //invoke function 
	else {
		window.onload=check_render_time() //function invoked again, since no event handler conflicts
	}


	function check_render_time()
	{
		//var began_loading already defined
		var ended_loading = (new Date()).getTime();
		render_time = ((ended_loading - began_loading) / 1000);
		setTimeout(write_render_time, 100);
	}

	function write_render_time()
	{
		var obj = document.getElementById("page_render_time");
		obj.innerHTML = " "+render_time+" ms";
	}