function $(id) {
	return document.getElementById(id);
}

var previous_menu = "";
var menu_timer;
function menu(name) {

	if (name != "") {
		clearTimeout(menu_timer);
		
		//open het menu, en sluit het vorige
		if (name != previous_menu) {
			try {
				$('children_'+previous_menu).style.display = 'none';
			} catch (E) {}
			$('children_'+name).style.display = '';
			previous_menu = name;
		}
	}
	else {
		if (previous_menu != "") {
			id = 'children_'+previous_menu;
			menu_timer = setTimeout("$('"+id+"').style.display = 'none'; previous_menu = ''",500);
		}
	}
}