JQuery :: Collapsible Vertical Menu - How To Target Next Element

I have a following menu that I'd like to be collapsible.
<ul id="#menu-sidebar">
<li>Menu item 1
<ul><li>Menu item 1.1</li>
<ul></li>
<li>Menu item 2
<ul><li>Menu item 2.1</li>
</ul></li></ul>
This collapses and expands them, but of course all at same time.
$('#menu-sidebarli ul').hide();
$("#menu-sidebarli").click(function(){
$("#menu-sidebarli").toggle();
$(this).toggleClass("active");
});
I've been trying to experiment with the .next() trying to get the next ul li ul element but with little luck.
$('#menu-sidebar li ul').hide();
$("#menu-sidebar li").click(function(){
$("#menu-sidebar ul li").next().toggle();
$(this).toggleClass("active");