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

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