function door(obj){
  baseObj = obj.parentNode.parentNode.childNodes;
  for (var i=0;i<baseObj.length;i++) {
    if (baseObj[i].className == 'closed' || baseObj[i].className == 'open') {
      baseObj[i].className = 'closed';
    }
  }
  obj = obj.parentNode;
  obj.className = 'open';
  return false;
}