/**
 * @author johnhardy
 */
var counter=300;
$(document).ready(
function() {

	setInterval(countDown,1000);

}
);

function countDown() {

	var min=Math.floor(counter/60);
	var sec=counter-(min*60);
	if(sec<=9) {

		sec="0"+sec;

	}

	$("#countdown").html(min+":"+sec);
	if(counter==0) {

		window.history.go();

	}
	counter--;
}