How to make tabbing between fields work in a Frame in wxPython

I am very new to wxPython and I have used the following tutorial to create a couple of TextCtrl fields and stuff.http://sebsauvage.net/python/gui/#import

Everything works except that I cant switch between the fields using the Tab button which is very annoying. How could I modify the example in that tutorial (with some more TextCtrl added to it) such that I can use tab to switch between the fields?

If you dont want to look at the tutorial, its basicalyl a frame with a bunch of TextCtrl put on it using a GridBagSizer.

When searching on the net all I found was "create a panel", but I tried that and since I am very new to wxPython it didnt work and I could not find a thorough tutorial on how to do that (and if possible Id like to stick with only a frame...)

Thanks!