Extjs 4.2.1 Grid panel not showing horizontal scroll bar when show/hide columns

Hi

Am new to Extjs and facing problems with grid panel.

When am adding more columns to the grid from the column menu show/hide columns, the grid is not getting the horizontal scroll bar when the grid is overflowed. This is cutting off my data in the grid and there is no way to check the data without the scroll bar. I have set autoscroll: true to the grid definition. The same problem when the window resizes the grid is not getting scrollbars.

Please post me any overrides or code snippets to help my situation.

Thanks in advance!!!!

Extjs 4.2.1 Grid panel not showing horizontal scroll bar when show/hide columns