if(document.images) {
    dog = new Array();
    dog[41] = new Image();
    dog[41].src = "/elearning/images/homepage/header_info_button.jpg";
    dog[42] = new Image();
    dog[42].src = "/elearning/images/homepage/header_info_rolo.jpg";
    dog[43] = new Image();
    dog[43].src = "/elearning/images/homepage/header_freedemos_button.jpg";
    dog[44] = new Image();
    dog[44].src = "/elearning/images/homepage/header_freedemos_rolo.jpg";
    dog[45] = new Image();
    dog[45].src = "/elearning/images/homepage/header_comm_button.jpg";
    dog[46] = new Image();
    dog[46].src = "/elearning/images/homepage/header_comm_rolo.jpg";
    dog[47] = new Image();
    dog[47].src = "/elearning/images/homepage/videoimage_button.jpg";
    dog[48] = new Image();
    dog[48].src = "/elearning/images/homepage/videoimage_rolo.jpg";
    dog[50] = new Image();
    dog[50].src = "/elearning/images/info/newsletter_button.jpg";
    dog[51] = new Image();
    dog[51].src = "/elearning/images/info/newsletter_rolo.jpg";
    dog[52] = new Image();
    dog[52].src = "/elearning/images/info/newsletter_archive_button.jpg";
    dog[53] = new Image();
    dog[53].src = "/elearning/images/info/newsletter_archive_rolo.jpg";
  }
    function switcher(from,to) {
    if(document.images) {
    document.images[from].src = dog[to].src;
    }
  }