$(document).ready(function () {
    function megaHoverOver() {
        $(this).find(".sub").fadeTo('fast', 0.9);
    }

    function megaHoverOut() {
            $(this).find(".sub").fadeTo('fast', 0);
    }

    var config = {
        sensitivity: 3, // number = sensitivity threshold (must be 1 or higher)    
        interval: 100, // number = milliseconds for onMouseOver polling interval    
        over: megaHoverOver, // function = onMouseOver callback (REQUIRED)    
        timeout: 500, // number = milliseconds delay before onMouseOut    
        out: megaHoverOut // function = onMouseOut callback (REQUIRED)    
    };

    $("ul#menu li .sub").css({'opacity': '0'});
    $("ul#menu li").hoverIntent(config);

});