ท่านใดมี code checkbox tree menu บ้างครับ ขอหน่อยครับ

<script type='text/javascript'>
var listTree={
	action:function(elm,chk,g){
		var  child=elm.parentNode.childNodes
			for(i=0;i<child.length;i++){
			if(child[i].tagName =="UL" || child[i].tagName =="OL"){
					this.loop(child[i],chk);
			}
		}

	},
	loop:function(elm,chk){
		var  child=elm.childNodes
		for(var i=0;i<child.length;i++){		
			if(child[i].tagName=="LI"){
				var child2=child[i].childNodes;
				for(var k=0;k<child2.length;k++){
					if(child2[k].tagName=="INPUT"){
							if(child2[k].getAttribute('type').toLowerCase()=='checkbox')
								child2[k].checked =(chk)?true:false;
					}else if(child2[k].tagName=="UL"){	
								this.loop(child2[k],chk);
					}
				}
			}
		}
	}

}
</script>


<ul class='list_tree'>
<li >
<input type='checkbox' onclick="listTree.action(this,this.checked)">A1
<ul>
	<li>
		<input type='checkbox' onclick="listTree.action(this,this.checked)">B1
		<ul>
			<li>
				<input type='checkbox' onclick="listTree.action(this,this.checked)">C1
				<ul>
					<li>
					<input type='checkbox' onclick="listTree.action(this,this.checked)">D1
					</li>
					<li>
					<input type='checkbox' onclick="listTree.action(this,this.checked)">D2
					</li>
				</ul>
			</li>
			<li>
				<input type='checkbox' onclick="listTree.action(this,this.checked)">C2
				<ul>
					<li>
					<input type='checkbox' onclick="listTree.action(this,this.checked)">D1
					</li>
					<li>
					<input type='checkbox' onclick="listTree.action(this,this.checked)">D2
					</li>
				</ul>
			</li>
			<li>
			<input type='checkbox' onclick="listTree.action(this,this.checked)">C3
			</li>
		</ul>
	</li>
	<li>
		<input type='checkbox' onclick="listTree.action(this,this.checked)">B2
	</li>
</ul>

</li>
<li>
	<input type='checkbox' onclick="listTree.action(this,this.checked)">A2
</li>
<ul>