$(document).ready(
   function(){
      $("ul#menu li ul").addClass("subnav");
      $("ul.subnav").parent().addClass("arrow");
      $("ul#menu li:first-child").addClass("first");
      $("ul#menu li:last-child").addClass("last");
      
      $("ul#menu li.arrow").hover(
	 function() { //When hovering...
	    $(this).find("ul.subnav").slideDown(0400).show(); //Slide down
	    $(this).find("ul.subnav").css('visibility', 'visible'); //bring back visibility while sliding down
	    $(this).addClass("hovering"); 
	 },
	 function() {
	    $(this).find("ul.subnav").css('visibility', 'hidden'); //instantly hide on mouseout
	    $(this).find("ul.subnav").hide(); //Slide back up
	    $(this).removeClass("hovering"); 
	 }
      );
   }
);