jQuery lightweight tree

tree.css

#container li {
	line-height:18px;	
}

#container li ins {
	display: inline-block;
	width:18px;
	height:18px;
	text-decoration:none;
	background-image:url('images/d.png'); // sprite image from jsTree
	background-repeat:no-repeat;
	background-position:0px 0px;
}

#container li ins.open {
	background-position:-18px 0px;
}

#container li ins.empty {
	background-image:none;
}

tree.js

        jQuery('#container li').each(function() {
		var elem = jQuery(this),
			has_children = elem.children('ul').length,
			toggler = '<ins class="'+(has_children ? "closed" : "empty")+'">&nbsp;</ins>'
		;
		elem.prepend(toggler);		
	});
	jQuery('#container').on('click', 'ins', function(){
		var ins = jQuery(this);
		ins.toggleClass('open closed');
		ins.siblings('ul').toggle();
	});

	jQuery('#container li ul').hide();