// Preload side navgation images (sidenav_) -
   sidenav_downloadOn = new Image();
   sidenav_downloadOn.src = "/serpenthead/images/sidenav_download_2.gif";
   sidenav_orderOn = new Image();
   sidenav_orderOn.src = "/serpenthead/images/sidenav_order_2.gif";
   sidenav_reviewsOn = new Image();
   sidenav_reviewsOn.src = "/serpenthead/images/sidenav_reviews_2.gif";
   sidenav_hintsOn = new Image();
   sidenav_hintsOn.src = "/serpenthead/images/sidenav_hints_2.gif";
   sidenav_storyOn = new Image();
   sidenav_storyOn.src = "/serpenthead/images/sidenav_story_2.gif";