var plus = new Image();
  plus.src = "/gif/menu_li.gif";
var minus = new Image();
  minus.src = "/gif/menu_li_2.gif";
var item = new Image();
  item.src = "/gif/menu_li_bw.gif";

function door(obj,linka){
  obj = obj.parentNode;
  obj.className = (obj.className == 'open') ? 'closed' : 'open';
  window.location = linka;
  return false;
}