$(function() {
    $("#nav-primary ul.menu ul").css({ display: 'none' });
    $("#nav-primary ul.menu li").hover(function() {
        $(this).find('a').next('.sub-menu')
            .stop(true, true).delay(50).animate({ "height": "show", "opacity": "show" }, 200 );
    }, function(){
        $(this).find('a').next('.sub-menu')
            .stop(true, true).delay(50).animate({ "height": "hide", "opacity": "hide" }, 200 );
    });

});