function SDMenu(id) {
  if (!document.getElementById || !document.getElementsByTagName)
  return false;
  this.menu = document.getElementById(id);
  this.submenus = this.menu.getElementsByTagName("div");
  this.remember = false;
  this.speed = 3;
  this.markCurrent = true;
  this.oneSmOnly = true;
}

SDMenu.prototype.init = function () {
  var mainInstance = this;
  for (var i = 0; i < this.submenus.length; i++) {
    var curr = this.submenus[i].getElementsByTagName("span")[0];
    curr.onclick = function () {
      mainInstance.toggleMenu(this.parentNode);
    };
  }

  if (this.submenus.length == 1) this.expandMenu(this.submenus[0]);

  if (this.markCurrent) {
    var links = this.menu.getElementsByTagName("a");
    for (var i = 0; i < links.length; i++)
    if (links[i].href == document.location.href) {
      links[i].className = "current";
      links[i].parentNode.className = "active";
      break;
    }
  }

  if (this.remember) {
    var regex = new RegExp("sdmenu_" + encodeURIComponent(this.menu.id) + "=([01]+)");
    var match = regex.exec(document.cookie);
    if (match) {
      var states = match[1].split("");
      for (var i = 0; i < states.length; i++)
      this.submenus[i].className = (states[i] == 0 ? "collapsed" : "");
    }
  }
};

SDMenu.prototype.toggleMenu = function (submenu) {
  if (submenu.className == "collapsed")
    this.expandMenu(submenu);
  else
    this.collapseMenu(submenu);
};

SDMenu.prototype.expandMenu = function (submenu) {
  var fullHeight = submenu.getElementsByTagName("span")[0].offsetHeight;
  var links = submenu.getElementsByTagName("a");
  for (var i = 0; i < links.length; i++)
  fullHeight += links[i].offsetHeight;
  var moveBy = Math.round(this.speed * links.length);
  var mainInstance = this;
  var intId = setInterval(function () {
    var curHeight = submenu.offsetHeight;
    var newHeight = curHeight + moveBy;
    if (newHeight < fullHeight)
      submenu.style.height = newHeight + "px";
    else {
      clearInterval(intId);
      submenu.style.height = "";
      submenu.className = "";
      mainInstance.memorize();
    }
  }, 30);

  this.collapseOthers(submenu);
};

SDMenu.prototype.collapseMenu = function (submenu) {
  var minHeight = submenu.getElementsByTagName("span")[0].offsetHeight;
  var moveBy = Math.round(this.speed * submenu.getElementsByTagName("a").length);
  var mainInstance = this;
  var intId = setInterval(function () {
    var curHeight = submenu.offsetHeight;
    var newHeight = curHeight - moveBy;
    if (newHeight > minHeight)
      submenu.style.height = newHeight + "px";
    else {
      clearInterval(intId);
      submenu.style.height = "";
      submenu.className = "collapsed";
      mainInstance.memorize();
    }
  }, 30);
};

SDMenu.prototype.collapseOthers = function (submenu) {
  if (this.oneSmOnly) {
    for (var i = 0; i < this.submenus.length; i++)
    if (this.submenus[i] != submenu && this.submenus[i].className != "collapsed")
    this.collapseMenu(this.submenus[i]);
  }

};

SDMenu.prototype.expandAll = function () {
  var oldOneSmOnly = this.oneSmOnly;
  this.oneSmOnly = false;
  for (var i = 0; i < this.submenus.length; i++)
  if (this.submenus[i].className == "collapsed")
  this.expandMenu(this.submenus[i]);
  this.oneSmOnly = oldOneSmOnly;
};

SDMenu.prototype.collapseAll = function () {
  for (var i = 0; i < this.submenus.length; i++)
  if (this.submenus[i].className != "collapsed")
  this.collapseMenu(this.submenus[i]);
};


SDMenu.prototype.initCurrent = function (submenu) {
  this.expandMenu(this.submenus[0]);
  for (var i = 0; i < this.submenus.length; i++) {
    if (this.submenus[i].className = "active") {
      this.expandMenu(this.submenus[i]);
    }
  }
};


SDMenu.prototype.memorize = function () {
  if (this.remember) {
    var states = new Array();
    for (var i = 0; i < this.submenus.length; i++)
    states.push(this.submenus[i].className == "collapsed" ? 0 : 1);
    var d = new Date();
    d.setTime(d.getTime() + (30 * 24 * 60 * 60 * 1000));
    document.cookie = "sdmenu_" + encodeURIComponent(this.menu.id) + "=" + states.join("") + "; expires=" + d.toGMTString() + "; path=/";
  }
};