wxPython, dynamically modify window

[Grant]

Hi, I am looking for a tip.  I have a panel and a checkbox.  When I 
check the checkbox, I would like to add buttons to the panel 
(dynamically).  When the checkbox is unchecked, the buttons should not 
appear (be deleted)---all the while, the window should resize if necessary.

If you have a simpler example, that is fine.  I just need a hint as to 
how you dynamically change the widgets and their layouts.

Looking at the wx demos, there is something close wx.lib.expando, but 
this is just modifying a particular widget.

Thanks.