Hi Shalini
I'm not sure what you mean by "Window Panes". Are you
possibly referring to the different areas you see inside a .CHM? If
so, you do have some control.
Over on the left side of the application, expand your Windows
pseudo-folder and double-click the window for your project. Once
you do this, you should see the window properties. Maybe this is
what you are referring to?
Cheers... Rick