Scrolltop menu

gistfile1.html

<div id="scrolltop">
  <span></span>
</div>

scrolltop.js

(function($) {
  Drupal.behaviors.asaleoScrollTop = {
    attach: function (context, settings) {
      $(window).scroll(function() {
        // Check scrollbar is top?
        if($(this).scrollTop() != 0) {
          // Fadein
          $('#scrolltop').fadeIn('slow');
        } else {
          // Fadeout and remove class active
          $('#scrolltop').fadeOut('slow');
          $('#scrolltop span').removeClass("active");
        }
      });
      $("#scrolltop").hover(
        //Mouseover, add hover class to span
        function () {
          $('#scrolltop span').addClass("hover");          
        }, 
        //Mouseout, remove the hover class
        function () {
          $('#scrolltop span').removeClass("hover");
        }        
        ).click(function() {        
        // Scroll to top when click and add an active class
        $('body,html').animate({
          scrollTop:0
        },400);
        $('#scrolltop span').addClass('active');
      });
    }
  };
})(jQuery);