$(document).ready(function() {
     $("#topnav li").prepend("<span></span>"); //Throws an empty span tag right before the a tag
     
     $("#topnav li").each(function() { //For each list item...
          var linkText = $(this).find("a").html(); //Find the text inside of the a tag
          $(this).find("span").show().html(linkText); //Add the text in the span tag
     }); 
     
     $("#topnav li").hover(function() { //On hover...
          $(this).find("span").stop().animate({ 
               marginTop: "-40" //Find the span tag and move it up 40 pixels
          }, 250);
     } , function() { //On hover out...
          $(this).find("span").stop().animate({
               marginTop: "0" //Move the span back to its original state (0px)
          }, 250);
     });
});