//-------------------------------------------------------------------------------
    if(document.images){
      var header_b01 = new Image();
          header_b01.src = "images/header_button-guestbook.gif";
      var header_b01_o = new Image();
          header_b01_o.src = "images/header_button-guestbook_o.gif";
      var header_b02 = new Image();
          header_b02.src = "images/header_button-media_resources.gif";
      var header_b02_o = new Image();
          header_b02_o.src = "images/header_button-media_resources_o.gif";
      var header_b03 = new Image();
          header_b03.src = "images/header_button-spinal_cord_research.gif";
      var header_b03_o = new Image();
          header_b03_o.src = "images/header_button-spinal_cord_research_o.gif";
      var header_b04 = new Image();
          header_b04.src = "images/header_button-the_triple_crown.gif";
      var header_b04_o = new Image();
          header_b04_o.src = "images/header_button-the_triple_crown_o.gif";
      var header_b05 = new Image();
          header_b05.src = "images/header_button-the_sport.gif";
      var header_b05_o = new Image();
          header_b05_o.src = "images/header_button-the_sport_o.gif";            
    }
//-------------------------------------------------------------------------------