Ext.onReady(function(){
      new Ext.Viewport({    //注意这里是Viewport，NO ViewPort
    enableTabScroll:true,
    layout:"border",
    items:[{title:"面板",
      region:"north",   //顶部面板
      height:50,
      html:'<h1>网站后台管理系统</h1>'
      },
      {
      title:"菜单",
      region:"west",    //左边菜单项，有按钮可控制伸缩的
      width:200,
      collapsible:true,
      html:"菜单栏"
      },
      {
      xtype:"tabpanel",   //选项卡
      region:"center",    
      items:[{title:"面板1",html:'<h1>面板1内容</h1>'},
        {title:"面板2",html:'<h1>面板2内容</h1>'},
        {title:"面板3",html:'<h1>面板3内容</h1>'}]
      }
      ]
      });
});