easyUI combobox级联

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><script type="text/javascript">$(function() {document.getElementById("user_editForm_id").style.display ="none";//地区 combobox 在onLoadSuccess里需要制定学校的Url 但是那时候学校控件还没初始化 所以在这里一开始就先初始化$('#user_editForm_schoolName').combobox({valueField:'id',textField:'name',editable:false,required:true});});</script><form id="user_editForm" method="post"><table><tr><td><input id="user_editForm_id" name="id" type="text" readonly="readonly"class="easyui-validatebox" data-options="required:true"hidden="true" /></td></tr><tr><th>District:</th><td><input id="system_user_user_addForm_districtName" name="districtId" class="easyui-combobox" data-options="     valueField: 'id',     textField: 'name',    required:true,     editable:false ,    url : '${pageContext.request.contextPath}/manage/district/getDistricts.do', onSelect: function(rec){  var url1 = '${pageContext.request.contextPath}/manage/school/findSchoolByDistrictId.do?id='+rec.id;  $('#user_editForm_schoolName').combobox('reload', url1);$('#user_editForm_schoolName').combobox('setValue','');  },onLoadSuccess:function(){var districtId= $('#system_user_user_addForm_districtName').combobox('getValue');var url2='${pageContext.request.contextPath}/manage/school/findSchoolByDistrictId.do?id='+districtId;$('#user_editForm_schoolName').combobox('reload', url2);} "/>  </td></tr><tr><th>School:</th><td><input id="user_editForm_schoolName" name="schoolId"/>  </td></tr></table></form>