var countDownInterval=300;
var countDownTime=countDownInterval+1;
function countDown(){
	countDownTime--;
	if (countDownTime <=0){
		countDownTime=countDownInterval;
		clearTimeout(counter)
		window.location.reload()
		return
	}
	counter=setTimeout("countDown()", 1000);
}

if (document.all||document.getElementById)
countDown()
else
window.onload=countDown