function mouse_btn(id,type) {
  var name = '/imgs/btn/';
  name = name + (type==2 ? "btn" + id + "_a.gif" : "btn" + id + "_i.gif");
  var img1 = new Image(212,23);
  img1.src = name;
  document.images['btn' + id].src=img1.src;
}