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 = false;
}
sdmenu.prototype.init = function() {
	var maininstance = this;
	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" : "");
		}
	}
};
//download by http://www.jb51.net
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=/";
	}
};