YAHOO.util.Event.onContentReady("mainMenu", function () {
    var oMenuBar = new YAHOO.widget.MenuBar("mainMenu", {
        autosubmenudisplay: true,
        hidedelay: 750,
        lazyload: true
    });
    oMenuBar.render();
    oMenuBar.show();
    
    // keep menu open when menu bar item is clicked
    oMenuBar.subscribe('click', function(p_sType, p_sArgs) {
        var o = p_sArgs[1].cfg.getProperty('submenu');
        if (o && !o.cfg.getProperty('visible')) {
            o.show();
        }
    });
});