function expandBlock(marker, id, offset, minheight) {
  // markerのidを持つタグの高さ+offsetの位置までidのオブジェクトの高さを広げる。minheightより小さい場合にはminheightに合わせる（NULLの場合は制限なし）
  top = document.getElementById(marker).offsetTop + offset;
  if (minheight != null && minheight > top) top = minheight;
  document.getElementById(id).style.height = top + "px";
}

function openwin(furl, w, h, option) {
  if (option == null) {
    option = "";
  } else {
    option = "," + option;
  }
  window.open(furl, '', "width=" + w +"," + "height=" + h + ",scrollbars=yes,resizable=yes" + option);
}

function changeButton(id, type) {
  if (type != "") type = "-" + type;
  document.getElementById(id).src = "http://www.topstudio.co.jp/images/" + id + type + ".jpg"; // GIFにしたい?
}