$(document).ready(function(){
  $('.down-list').width($('.dropdown-menu').width()-2);
  $('.down-list').css("width","200px");
  $('.down-list').css("display","none");
  $('.menu-first').hover(
    function () {
      $('.menu-first', this).addClass('slide-down');
      $('.down-list', this).slideDown(100);
    },
    function () {
      obj = this;
      $('.down-list', this).slideUp(100, function(){ $('.menu-first', obj).removeClass('slide-down'); });
    }
  );
});