function SDMenu(id) {
  if (!document.getElementById || !document.getElementsByTagName)
    return false;
  this.menu = document.getElementById(id);
  this.submenus = this.menu.getElementsByTagName("div");
}
SDMenu.prototype.init = function() {
  for (var i = 0; i < this.submenus.length; i++) {
    if (this.submenus[i].className == "collapsed") {
      var newHeight = this.submenus[i].getElementsByTagName("span")[0].offsetHeight;
      this.submenus[i].style.height = newHeight + "px";
    } else {
      this.submenus[i].style.height = "auto";
    }
  }
};