document.observe("dom:loaded", function() {
    $$('#mainTool a').each(function(el) {
        el.observe('mouseover', function() {
            var subMenu = el.up().select('ul')[0];
            if (subMenu) {
                subMenu.show();
                subMenu.up().addClassName('active');

                var hideList = function(e) {
                    var elt = $(Event.element(e));
                    if (!elt.descendantOf(subMenu.up())) {
                        subMenu.hide();
                        subMenu.up().removeClassName('active');
                    }
                };
                Event.observe(document, 'mouseover', hideList.bind(this));
            }
        });
    });
});