function initMenu(topMenuSelector, menuItemSelector) {
    $(window).addEvent("load", function() {
        $$(topMenuSelector).each(function(menu) {
            // use 'menu' in a closure manner - because event.element() will return bubbled source (a.menuTitle) not ".topMenu
            menu.addEvent('mouseover', function(event) {
                menu.getElements(menuItemSelector).each(function(submenu) {
                    submenu.addClass("parentHover");
                });
            });
            menu.addEvent('mouseout', function(event) {
                menu.getElements(menuItemSelector).each(function(submenu) {
                    submenu.removeClass("parentHover");
                });
            });
        });
    });
}

initMenu(".head_menu-01_act", ".head_menu-01-l2");
initMenu(".head_menu-01", ".head_menu-01-l2");
initMenu(".head_menu-02_act", ".head_menu-02-l2");
initMenu(".head_menu-02", ".head_menu-02-l2");