if (document.images) {
   img1 = new Image(); img1.src = "http://www7.plala.or.jp/tabifufu/ring/image/navi-W/backL.gif";
   img2 = new Image(); img2.src = "http://www7.plala.or.jp/tabifufu/ring/image/navi-W/listL.gif";
   img3 = new Image(); img3.src = "http://www7.plala.or.jp/tabifufu/ring/image/navi-W/homeL.gif";
   img4 = new Image(); img4.src = "http://www7.plala.or.jp/tabifufu/ring/image/navi-W/randomL.gif";
   img5 = new Image(); img5.src = "http://www7.plala.or.jp/tabifufu/ring/image/navi-W/nextL.gif";
}
function setImage(img, image) {
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      img.src = image;
   }
}