$(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);
    });

});