extjs grid做的表格,在FireFox里能正常显示,在IE6中却显示不出来,请大侠们不吝赐教!谢谢

extjs版本3.2
这个问题的源码如下:
var modifyRecord=new Array();/* 将修改后的行记录下来 */
function handlesurebutton() {
     var grade = document.getElementById("gradeName").value;
     var oneClass = document.getElementById("oneClassName").value;
     if (grade != '' && oneClass != '') {
         /* TableModel.getTableModel()为dwr调用 */
         TableModel.getTableModel(grade, oneClass, function(data) {
             var store = new Ext.data.Store( {
                 proxy:new Ext.data.MemoryProxy(data),
                 reader:new Ext.data.JsonReader({id:'parentId'},[{name:'parentId'},
                                                    {name:'parentId1'},
                                                    {name:'gradeName'},
                                                    {name:'oneClassName'},
                                                    {name:'stuName'},
                                                    {name:'pp1'},
                                                    {name:'pp2'}])
                


             });
             store.load();
            
//             var store=new Ext.data.JsonStore({data:dt,fields:['parentId','parentId1','gradeName','oneClassName','stuName','pp1','pp2']});
//             store.load();
             var colm = new Ext.grid.ColumnModel( [ {
                 header : '记录号1',
                 dataIndex : 'parentId'
             }, {
                 header : '记录号2',
                 dataIndex : 'parentId1'
             },{
                 header : '年级',
                 dataIndex : 'gradeName'
             }, {
                 header : '班级',
                 dataIndex : 'oneClassName'
             }, {
                 header : '学生',
                 dataIndex : 'stuName'
             }, {
                 header : '家长电话1',
                 dataIndex : 'pp1',
                 editor : new Ext.form.TextField()
             }, {
                 header : '家长电话2',
                 dataIndex : 'pp2',
                 editor : new Ext.form.TextField()


             } ]);
             var tablediv=document.getElementById("table1");
             tablediv.innerHTML="";
             var grid = new Ext.grid.EditorGridPanel( {
                 renderTo : 'table1',
                 title : '家长电话管理',
                 height : 200,
                 width : 603,
                 lodaMask : true,
                 stripeRows : true,
                 cm : colm,
                 store : store,
                 clicksToEdit : 1,
                 listeners:{
                    afteredit:function(obj){
                     var r=obj.record;
                     var pid=r.get("parentId");
                     var pid1=r.get("parentId1");
                     var grade=r.get("gradeName");
                     var oneclass=r.get("oneClassName");
                     var stuname=r.get("stuName");
                     var p1=r.get("pp1");
                     var p2=r.get("pp2");
                     var b={parentId:pid,parentId1:pid1,gradeName:grade,oneClassName:oneclass,stuName:stuname,pp1:p1,pp2:p2};
                     checkdata(b);
                     modifyRecord.push(b);/*此处未对重复保存记录进行检查*/
             }
             }
             });
            
            
            
         });
     }
}