jQuery code to fade in a dropdown menu when hovered over.

FadeInOnHover

    <script type="text/javascript" src="http://code.jquery.com/jquery-1.8.3.min.js"></script>

    <script type="text/javascript">
        $(document).ready(function () {

            $("#nav li").has("ul").hover(function () {
                $(this).addClass("current").children("ul").show().hide().fadeIn(500);
            }, function () {
                $(this).removeClass("current").children("ul").stop(true, true).css("display", "none");
            });

        });
</script>