关于Ext里面TabPanel的布局问题

Question

请教下各位，为什么我下面的Window 里面的的TAB面板没有撑开？（代码直接复制到HTML里面就可以运行）Ext.onReady(function(){
              Ext.QuickTips.init(); 
              win =  new Ext.Window({
            title: '新增记录',
                    width: 600,
                    height: 280,
                    layout: 'fit',
                    plain: true,
                    modal: true,//锁定背景
                    buttonAlign: 'center',
                    items: {
                     xtype:'form',
                     layout: 'fit',
                     id:'addform',
                 labelAlign: 'right',
                     items:[{
                     xtype:'tabpanel',
                     activeTab :0,
                     id:'addPanel',
                     items:[{
                     title:'申请成果信息',
                     layout :'fit',
                     items:{
            layout:'column',
            items:[{
                     layout:'form',
                     columnWidth : .5,
                     border:false,
                     items:[
                     { // fields
                             fieldLabel:'成果类别',
                             name:'CGLB',
                             xtype:'textfield',
                             anchor:'90%'
                        },{
                         xtype:'hidden',
                         name:'SQR'
                        },{
                         xtype:'hidden',
                         name:'DEPARTID'
                        },{
                         xtype:'hidden',
                         name:'DEPARTNAME'
                        }//后台需要加申请日期
                     ]
                     },{
                     layout:'form',
                     columnWidth : .5,
                     border:false,
                     items:[
                     { // fields
                             fieldLabel:'隶属科室',
                             name:'LSKS',
                             xtype:'textfield',
                             anchor:'90%'
                        }
                     ]
                     },{
                     layout:'form',
                     columnWidth : .5,
                     border:false,
                     items:[
                     { // fields
                             fieldLabel:'主要完成人',
                             name:'ZYWCR',
                             xtype:'textfield',
                             anchor:'90%'
                        }
                     ]
                     }]        
                     }
                     }]
                     }]
                    },
                    buttons:[{text:'提  交' },{text:'保  存'},{text:'取  消'}]
            
            });                win.show(Ext.getBody());
             })

Answer 1

里面的的TAB面板没有撑开？
----------
什么意思？？展开了啊

Answer 2

呵呵，搞定了，原因是：我用的2.0版本，要用2.2之后的版本才会有效果，我先看一看FireFox，为什么会这样，也希望大家能指教下为什么会出这种情况？

Answer 3

2.2版本的form样式是这样：
<form id="ext-gen16" class="x-panel-body x-panel-body-noheader x-form" method="post" style="width: 582px; height: 208px;">2.0版本的form样式是这样：
<form id="ext-gen80" class="x-form" method="post">。。