function show(id) {
  var bl = document.getElementById("sub-" + id);
  if(bl.className == "hidden") {
    bl.className = "";
    document.getElementById("img-" + id).src = "../shop/work/pictures/system/v1_on.gif";
  }
  else {
    bl.className = "hidden";
    document.getElementById("img-" + id).src = "../shop/work/pictures/system/v1_off.gif";
  }
  return false;
}