function tree2(menu_class,menu_id) {
  var div=document.getElementById(menu_id);
  if (div.style.display == "block") {
    div.style.display="none";
  } else {
    var sib=div.parentNode.childNodes;
    for (var i=0; i < sib.length; i++) {
      if (sib[i].className == menu_class) {
        sib[i].style.display="none";
      }
      div.style.display="block";
    }
  }
}