Ext window 相对位置

var win = Ext.create('Ext.Window', {
        title: 'Right Header, plain: true',
        width: 400,
        height: 50,
        layout: 'fit',
        items: {
            border: false
        }
    });
    win.show();
    win.getEl().anchorTo(Ext.get("pos_id"),'tl-tr',[100,-20]);