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>
------最佳解决方案--------------------------------------------------------

	Ext.onReady(function() {
	    var refThis = this;
	    refThis.panel = new Ext.TabPanel({
	        //renderTo: Ext.getBody(),