Unable to enable vertical scrollbar in ExtJS livegrid

I was trying to implement the ExtJs livegrid extension in my application to support rendering of a huge amount of data. I was able to scroll down the data using the arrow开发者_高级运维 key. However, I was unable to scroll using the vertical scrollbar as it is not visible. I tried to search on the web but was not able to locate any information. I tried to set autoScroll:true in livegrid.GridPanel but no use. What properties do I have to set in order to see the vertical scrollbar? Thanks in advance for any help.

here the exerpt from working code, hope it works for you. Cheers

 myView = new Ext.ux.grid.livegrid.GridView({
  nearLimit : 100,
  scrollDelay: 10,
  forceFit: true,
  emptyText: "Geen data gevonden",
  loadMask  : {msg :  'Bezig met laden...'}
});

grid = new Ext.ux.grid.livegrid.EditorGridPanel({
  id              : "grid",
  enableDragDrop  : false,
  loadMask        : true,
  clicksToEdit    : 1,
  layout          :'anchor',
  cm              : cm,
  columnLines     : true,
  autoHeight      : false,
  store           : store,
  selModel        : new Ext.ux.grid.livegrid.RowSelectionModel(),
  view            : myView
})

tabs = new Ext.TabPanel({
  margins:'0 0 0 0',
  padding:'0 0 0 0',
  activeTab: 4,
  layoutOnTabChange:false,
  id: 'tabs',
  items:[
    {
       id: 'tab1Midoc',
       title: 'title',
       layout:'fit',
       items: [grid]
    }
  ]
});

viewport = new Ext.Viewport({
 layout:'border',
 items:[{
   region: 'center',
   layout:'fit',
   title: 'title',
   id:'center',
   border: true,
   items:[tabs]
 }]
});