jquery treeview 使用时候,只展示一层问题

			 	$("#categorys").treeview({
					persist: "location",
					control: "#treecontrol",
					unique: true
				});//只展开一层			 	



$("#categorys").treeview({
					control: "#treecontrol",
					persist: "cookie"
				});
		  	});//展开所有层.



		                <div class="areaBody">
							<div id="treecontrol">
								[<a href="#">Collapse</a>]&nbsp;[<a href="#">Expand</a>]&nbsp;[<a href="#">Toggle</a>]
							</div>
				            <ul id="categorys">
				             	<li id="root">
				             	</li>
				            </ul>
		               	</div> 		  	});