求教关于Ext的有关问题

求教关于Ext的问题
想请问一个问题，如何在一个ExtPanel中加入一个ExtTabPanel，如图

想把下面的ExtTabPanel加入到上面的ExtPanel里面，怎么写呢？代码如下：
 <script>
        Ext.onReady(function(){
         var refThis=this;
         refThis.panel=   new Ext.Panel({
                renderTo:Ext.getBody(),
                title:"面板头部header",
                width:400,
                height:200,
                layout:"column",
                
                });
             refThis.panel=new Ext.TabPanel({
            renderTo:Ext.getBody(),
            width:300,
            height:200,
            activeTab:0,
            items:[new Ext.Panel({
                title:"面板1",
                height:30,
                html:'面板1'
                }),new Ext.Panel({
                    title:"面板2",
                    height:30,
                    html:'面板2'
                }),new Ext.Panel({
                    title:"面板3",
                    height:30,
                    html:'面板3'
                 })]
           });
                
          });
          
    </script>
[最优解释]

Ext.onReady(function() {
    var refThis = this;
    refThis.panel = new Ext.TabPanel({
        //renderTo: Ext.getBody(), 
 
        width: 300,
        height: 200,
        activeTab: 0,
        items: [new Ext.Panel({
                title: "面板1",
                height: 30,
                html: '面板1'
            }), new Ext.Panel({
                title: "面板2",
                height: 30,
                html: '面板2'
            }), new Ext.Panel({
                title: "面板3",
                height: 30,
                html: '面板3'
            })]
    });
    refThis.panel = new Ext.Panel({
        renderTo: Ext.getBody(),
        title: "面板头部header",
        width: 400,
        height: 200,
        layout: "column",
        items: [refThis.panel]
    });
});