"Back to top" link does not appear

Hello,

Thanks for this module.
I would like to enable "back to top" functionality (like on http://www.colorado.edu/)
When i enable the "scroll to" option, the link "show photo" appear in the page's footer.
But then this link does not transform to "Back to top".
It should be working with these waypoint function:

if (Drupal.settings.backstretchScrollTo) {

        $("#footer").waypoint(function(){
          $("#backstretch-scrollto").text("Back to Top").attr("href", "#page");
        });

        $("#main-menu").waypoint(function(){
          $("#backstretch-scrollto").text("View Photo").attr("href", "#backstretchmargin");
        });

BTW i am using the omega theme.

Could you explain how to implement this ?