extjs报’id'为空或不是对象，哎，真垃圾！！！ - Web 开发 / Ajax
请帮忙看看吧，找不到原因啊。谢谢了！
/** 专题班评价的JS页面*/Ext.onReady(function(){//数据var store= new Ext.data.Store({ reader:new Ext.data.JsonReader({ root : 'root', idProperty:'courseName', //********必须加！！！ totalProperty : 'totalCount', fields:[{ name : 'courseName' } ]}), proxy : new Ext.data.HttpProxy({ url : ctPath +'/EvaluationAction!getEvalueResultInfo.do' }), sortInfo :{field: "courseName", direction: "ASC"}, remoteSort: true }); //用于显示的GridPannel，主窗口************************************************** //主面板gridvar sm=new Ext.grid.CheckboxSelectionModel();var ztevalgrid=new Ext.grid.GridPanel({ //title:'专题班评估', renderTo:'evaluation-div', width:Ext.getCmp("tabpanel").getInnerWidth()-2, height:Ext.getCmp("tabpanel").getInnerHeight()-2, sm:sm, store:store, tbar:[ new Ext.ux.form.SearchField({ store : store, width : 260 //data: '' }),{ text:'评价', handler:function(){ //ztb_evalue.show(); }, iconCls : "icon-add" }], columns:[ sm, {id:'courseName',header:'专题班名称',width:230,dataIndex:'courseName',sortable:true}, //{header:'专题班代码',width:100,dataIndex:'evaluCourseId',sortable:true}, //{header:'总分',width:80,dataIndex:'evaluCourseId',sortable:true}, //{header:'培训设计',width:80,dataIndex:'evaluCourseId',sortable:true}, //{header:'培训实施',width:80,dataIndex:'evaluCourseId',sortable:true}, //{header:'培训管理',width:80,dataIndex:'evaluCourseId',sortable:true}, //{header:'培训效果',width:80,dataIndex:'evaluCourseId',sortable:true}, //{header:'评估率',width:80,dataIndex:'evaluCourseId',sortable:true}, //{header:'备注',width:130,dataIndex:'evaluCourseId',sortable:true} ], bbar: new Ext.PagingToolbar({ pageSize: 25, store: store, displayInfo: true }) }); //用于显示的GridPannel，主窗口^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ //数据载入 ******必须加！！！ store.load({ params : { start : 0, limit : 15 } }); })