if(document.images) {
  var imgs = new Array();
  imgs[0] = new Image();  imgs[0].src = "imgs/side_aboutus01.gif"; 
  imgs[1] = new Image();  imgs[1].src = "imgs/side_aboutus02.gif";
  imgs[2] = new Image();  imgs[2].src = "imgs/side_tips01.gif";
  imgs[3] = new Image();  imgs[3].src = "imgs/side_tips02.gif"; 
  imgs[4] = new Image();  imgs[4].src = "imgs/side_chargers01.gif";
  imgs[5] = new Image();  imgs[5].src = "imgs/side_chargers02.gif"; 
  imgs[6] = new Image();  imgs[6].src = "imgs/side_accessories01.gif";
  imgs[7] = new Image();  imgs[7].src = "imgs/side_accessories02.gif";
  imgs[8] = new Image();  imgs[8].src = "imgs/side_ipod01.gif";
  imgs[9] = new Image();  imgs[9].src = "imgs/side_ipod02.gif";
  imgs[10] = new Image();  imgs[10].src = "imgs/side_catalog01.gif";
  imgs[11] = new Image();  imgs[11].src = "imgs/side_catalog02.gif";
}

function chgimg(id, imgname) {
  if(document.images) {
    if(imgs[imgname]) {
      document.images[id].src = imgs[imgname].src;
    }
    else {
      document.images[id].src = imgname;
    }
  }
}