ztree 点击文本框弹出下拉框

<link rel="stylesheet" href="${ctx}/res/js/ztree/CSS/demo.css" type="text/css"/><link rel="stylesheet" href="${ctx}/res/js/ztree/css/zTreeStyle/zTreeStyle.css" type="text/css"/><script type="text/javascript" src="${ctx}/res/js/ztree/js/jquery.ztree.core-3.5.js"></script>
<input onclick="showMenu();return false;"/>
var setting = {	view: {		dblClickExpand: false	},	data: {		simpleData: {			enable: true		}	},	callback: {		onClick: onClick	}};function onClick(e, treeId, treeNode) {	var zTree = $.fn.zTree.getZTreeObj("treeDemo"),	nodes = zTree.getSelectedNodes();	menuName = "";	menuId = "";	nodes.sort(function compare(a,b){return a.id-b.id;});		var isParent = nodes[0].getParentNode();	var isChildren = nodes[0].children;		if((!isParent && !isChildren) || (isParent)){		for (var i=0, l=nodes.length; i<l; i++) {			menuName += nodes[i].name + ",";			menuId += nodes[i].id + ","; 		}		if (menuName.length > 0 ) menuName = menuName.substring(0, menuName.length-1);		if (menuId.length > 0 ) menuId = menuId.substring(0, menuId.length-1);				$("#menuName").val(menuName);		$("#menuId").val(menuId);	}}function showMenu() {	var cityObj = $("#menuName");	var cityOffset = $("#menuName").offset();	$("#menuContent").css({left:cityOffset.left + "px", top:cityOffset.top + cityObj.outerHeight() + "px"}).slideDown("fast");	$("body").bind("mousedown", onBodyDown);	var width = cityObj.css("width");	$("#treeDemo").css("width",parseInt(width)-5);}function hideMenu() {	$("#menuContent").fadeOut("fast");	$("body").unbind("mousedown", onBodyDown);}function onBodyDown(event) {	if (!(event.target.id == "menuContent" || $(event.target).parents("#menuContent").length>0)) {		hideMenu();	}}$(document).ready(function(){	$.fn.zTree.init($("#treeDemo"), setting, zNodes);});