var timeout    = 500;
var closetimer = 0;
var menuitem = 0;

function menu_open() {
	menu_canceltimer();
	menu_close();
	menuitem = $(this).find('ul').css('visibility', 'visible');
}

function menu_close() {
	if(menuitem) menuitem.css('visibility', 'hidden');
}

function menu_timer() {
	closetimer = window.setTimeout(menu_close, timeout);
}

function menu_canceltimer() {
	if(closetimer) {
		window.clearTimeout(closetimer);
      	closetimer = null;
	}
}