//Controls the speed of jQuery, set to 1 milisecond
$(document).ready(function () {

    $('div.top_menu_button').mouseenter(function () {
    $(this).find('div.sub_menu3').slideDown(1);
    });

    $('div.top_menu_button').mouseleave(function () {
    $(this).find('div.sub_menu3').slideUp(1);
    });

});