Applying horizontal scroll in Extjs

I wan to apply horizontal scrollbar in my panel(ExtJS) my code is...

var reportPanel = new Wtf.开发者_高级运维Panel({
    border: false,
    title: "Chart View",
    autoScroll: true,
    iconCls: "pwndCRM piechartIcon",
    bodyStyle: 'background:white',
    layout: 'border',
    tbar: [this.pieChartButton, this.barChartButton],
    closable: true,
    items: [new Wtf.Panel({
        id: mainpanid + "center_panel",
        autoScroll: true,
        //columnWidth:.47,
        layout: "fit",
        border: true,
        region: "center",
        width: '50%',
        collapsible: true
    })
      , new Wtf.Panel({
        id: mainpanid + "east_panel",
        autoScroll: true,
        border: true,
        layout: "fit",
        //columnWidth:.48,
        region: "east",
        width: '50%',
        collapsible: true

    })
    ]
});

It is not working can anybody tell what is wrong with code...?