Disable resizing of pane in MDI MFC app

I created simple MFC(VS2010) MDI application.
I need the panes to be resizeable or non-resizeable according to clicking a button.

How should I do it?

http://www.codeguru.com/forum/showthread.php?t=432936
FAQ
https://www.google.com/search?hl=en&...w=1333&bih=800