home_img_out = new Image();
  home_img_out.src = "images/logo_avocado_off.jpg";

  home_img_over = new Image();
  home_img_over.src = "images/logo_avocado_on.jpg";

  submit_img_out = new Image();
  submit_img_out.src = "images/btn_submit_off.jpg";

  submit_img_over = new Image();
  submit_img_over.src = "images/btn_submit_on.jpg";

  news_img_out = new Image();
  news_img_out.src = "images/btn_latest_news_off.jpg";

  news_img_over = new Image();
  news_img_over.src = "images/btn_latest_news_on.jpg";

  newsletter_img_out = new Image();
  newsletter_img_out.src = "images/btn_newsletter_off.jpg";

  newsletter_img_over = new Image();
  newsletter_img_over.src = "images/btn_newsletter_on.jpg";


  function display(imgName, imgUrl) {
    if (document.images && typeof imgUrl != 'undefined')
      document[imgName].src = imgUrl.src;
  }