Toggle Fonts without font-menue

[David Feest]

Hi!

I use two different types of courier font -- cronyx or adobe --
depending on if I need the Cyrillic letters or the German Umlauts.
Font menue provides a way, of switching fonts on the fly. However, I'd
like to toggle between the fonts through a key-binding. Unfortunately
I haven't managed to find out, which command is responsible for font
change.

Thanks in advance, 

David