Mozilla key mappings

[Mnemia]

Does anyone know how to remap keys to GUI commands in Mozilla? I'm trying to get some of the 'extra' keys on my laptop to work with forward, back, reload, etc. and the only part I can't figure out (after some searching here and on Google) is how to set up the Mozilla configs to use the keystroke/combinations I specify.

I have xmodmap set up correctly and it works fine for generating bash commands to launch programs and control Fluxbox. I've mapped the keys I want to F19 and F20, and now I need to know how to tell Mozilla I want it to do such and such action when F20 is pressed.

I've tried looking through their docs and I couldn't find anything easily on how to do this. Anyone know how to do this or can point me to some resource I've missed and let me figure it out myself?