if(document.images) {
 var imgs = new Array();

 imgs[1] = new Image();  imgs[1].src = "img/bt01a.gif";
 imgs[2] = new Image();  imgs[2].src = "img/bt02a.gif";
 imgs[3] = new Image();  imgs[3].src = "img/bt03a.gif";
 imgs[4] = new Image();  imgs[4].src = "img/bt04a.gif";
 imgs[5] = new Image();  imgs[5].src = "img/bt05a.gif";
 imgs[6] = new Image();  imgs[6].src = "img/bt06a.gif";
 imgs[7] = new Image();  imgs[7].src = "img/bt07a.gif";
 imgs[8] = new Image();  imgs[8].src = "img/bt08a.gif";

 imgs[11] = new Image();  imgs[11].src = "img/top05a.gif";

 imgs[12] = new Image();  imgs[12].src = "img/a_bt01a.gif";
 imgs[14] = new Image();  imgs[14].src = "img/a_bt03a.gif";
 imgs[15] = new Image();  imgs[15].src = "img/a_bt04a.gif";

 imgs[16] = new Image();  imgs[16].src = "img/f_bt01a.gif";
 imgs[17] = new Image();  imgs[17].src = "img/f_bt02a.gif";
 imgs[18] = new Image();  imgs[18].src = "img/f_bt03a.gif";

 imgs[19] = new Image();  imgs[19].src = "img/mbt01a.gif";
 imgs[20] = new Image();  imgs[20].src = "img/mbt02a.gif";
 imgs[21] = new Image();  imgs[21].src = "img/mbt03a.gif";
 imgs[22] = new Image();  imgs[22].src = "img/mbt04a.gif";
 
 imgs[23] = new Image();  imgs[23].src = "img/mbt01a.gif";
 imgs[24] = new Image();  imgs[24].src = "img/mbt02a.gif";
 imgs[25] = new Image();  imgs[25].src = "img/mbt03a.gif";
 imgs[26] = new Image();  imgs[26].src = "img/mbt04a.gif";

 imgs[27] = new Image();  imgs[27].src = "img/mbt01a.gif";
 imgs[28] = new Image();  imgs[28].src = "img/mbt02a.gif";
 imgs[29] = new Image();  imgs[29].src = "img/mbt03a.gif";
 imgs[30] = new Image();  imgs[30].src = "img/mbt04a.gif";



}

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