$(function() {
  // set opacity to nill on page load
  $("ul#menu span").css("opacity","0");
  // on mouse over
  $("ul#menu span").hover(function () {
						  // animate opacity to full
						  $(this).stop().animate({
												 opacity: 1
												 }, 'slow');
						  },
						  // on mouse out
						  function () {
						  // animate opacity to nill
						  $(this).stop().animate({
												 opacity: 0
												 }, 'slow');
						  });
  });