if (document.images) {
  image1on = new Image();
  image1on.src = "/images/nav_01b.gif";
  image1off = new Image();
  image1off.src = "/images/nav_01a.gif";
  
  image2on = new Image();
  image2on.src = "/images/nav_02b.gif";
  image2off = new Image();
  image2off.src = "/images/nav_02a.gif";

  image3on = new Image();
  image3on.src = "/images/nav_03b.gif";
  image3off = new Image();
  image3off.src = "/images/nav_03a.gif";
 
  image4on = new Image();
  image4on.src = "/images/nav_04b.gif";
  image4off = new Image();
  image4off.src = "/images/nav_04a.gif";
  
  image5on = new Image();
  image5on.src = "/images/nav_05b.gif";
  image5off = new Image();
  image5off.src = "/images/nav_05a.gif";
  
  image6on = new Image();
  image6on.src = "/images/nav_06b.gif";
  image6off = new Image();
  image6off.src = "/images/nav_06a.gif";
  
  image7on = new Image();
  image7on.src = "/images/nav_07b.gif";
  image7off = new Image();
  image7off.src = "/images/nav_07a.gif";
    
  image8on = new Image();
  image8on.src = "/images/nav_08b.gif";
  image8off = new Image();
  image8off.src = "/images/nav_08a.gif";
  
  sub1on = new Image();
  sub1on.src = "/images/navi_sub_01b.jpg";
  sub1off = new Image();
  sub1off.src = "/images/navi_sub_01a.jpg";

  sub2on = new Image();
  sub2on.src = "/images/navi_sub_02b.jpg";
  sub2off = new Image();
  sub2off.src = "/images/navi_sub_02a.jpg";
  
  sub3on = new Image();
  sub3on.src = "/images/navi_sub_03b.jpg";
  sub3off = new Image();
  sub3off.src = "/images/navi_sub_03a.jpg";
  
  sub4on = new Image();
  sub4on.src = "/images/sub02_nav02b.gif";
  sub4off = new Image();
  sub4off.src = "/images/sub02_nav02a.gif";

  sub5on = new Image();
  sub5on.src = "/images/navi_sub_05b.jpg";
  sub5off = new Image();
  sub5off.src = "/images/navi_sub_05a.jpg";

  sub6on = new Image();
  sub6on.src = "/images/navi_sub_06b.jpg";
  sub6off = new Image();
  sub6off.src = "/images/navi_sub_06a.jpg";

  sub7on = new Image();
  sub7on.src = "/images/navi_sub_07b.jpg";
  sub7off = new Image();
  sub7off.src = "/images/navi_sub_07a.jpg";
  
  sub_01aon = new Image();
  sub_01aon.src = "/images/sub01_nav01b.gif";
  sub_01aoff = new Image();
  sub_01aoff.src = "/images/sub01_nav01a.gif";

  sub_02aon = new Image();
  sub_02aon.src = "/images/sub01_nav02b.gif";
  sub_02aoff = new Image();
  sub_02aoff.src = "/images/sub01_nav02a.gif";

  sub_03aon = new Image();
  sub_03aon.src = "/images/sub02_nav01b.gif";
  sub_03aoff = new Image();
  sub_03aoff.src = "/images/sub02_nav01a.gif";

  sub_04aon = new Image();
  sub_04aon.src = "/images/sub02_nav02b.gif";
  sub_04aoff = new Image();
  sub_04aoff.src = "/images/sub02_nav02a.gif";
  
  sub_05aon = new Image();
  sub_05aon.src = "/images/sub02_nav03b.gif";
  sub_05aoff = new Image();
  sub_05aoff.src = "/images/sub02_nav03a.gif";

  sub_06aon = new Image();
  sub_06aon.src = "/images/sub02_nav04b.gif";
  sub_06aoff = new Image();
  sub_06aoff.src = "/images/sub02_nav04a.gif";

  sub_07aon = new Image();
  sub_07aon.src = "/images/sub04_nav01b.gif";
  sub_07aoff = new Image();
  sub_07aoff.src = "/images/sub04_nav01a.gif";
  
  sub_08aon = new Image();
  sub_08aon.src = "/images/sub04_nav02b.gif";
  sub_08aoff = new Image();
  sub_08aoff.src = "/images/sub04_nav02a.gif";

  sub_09aon = new Image();
  sub_09aon.src = "/images/sub04_nav03b.gif";
  sub_09aoff = new Image();
  sub_09aoff.src = "/images/sub04_nav03a.gif";

  sub_10aon = new Image();
  sub_10aon.src = "/images/sub04_nav04b.gif";
  sub_10aoff = new Image();
  sub_10aoff.src = "/images/sub04_nav04a.gif";

  sub_11aon = new Image();
  sub_11aon.src = "/images/sub04_nav05b.gif";
  sub_11aoff = new Image();
  sub_11aoff.src = "/images/sub04_nav05a.gif";

  sub_12aon = new Image();
  sub_12aon.src = "/images/sub04_nav06b.gif";
  sub_12aoff = new Image();
  sub_12aoff.src = "/images/sub04_nav06a.gif";

  sub_13aon = new Image();
  sub_13aon.src = "/images/sub04_nav07b.gif";
  sub_13aoff = new Image();
  sub_13aoff.src = "/images/sub04_nav07a.gif";
}

function changeImages() {
  if (document.images) {
    for (var i=0; i<changeImages.arguments.length; i+=2) {
      document[changeImages.arguments[i]].src = eval(changeImages.arguments[i+1] + ".src");
    }
  }
}