var timerState = false;

function menu_on() {
	stop_timer();
	document.all.menu.style.visibility='visible';
}

function menu_off() {
	document.all.menu.style.visibility='hidden';
	chg_button("services","off");
}

function stop_timer () {
	if (timerState) {
		clearTimeout(timerApp);
		timerState = false;
	}
}

function start_timer () {
	stop_timer();
	timerState = true;
	timerApp = setTimeout('menu_off();chg_button("services","off");',500);
}