Where is Gnome logout script/program?

[William Case <billlinux rogers com>]

Hi;

I want to build myself a logout script that cleanly closes Firefox and
Epiphany before logging out of a session.  I will bind the script to a
logout icon.

I do not want to destroy Firefox's and Epiphany recovery ability except
for the occasions when I would have deliberately closed those programs
before logout anyways.

I would like to see how 'kill' and/or 'term' or whatever are used by
Gnome and duplicate that process with the addition of first closing the
two browsers.

'locate' and 'whereis' have been unhelpful.  
-- 
Regards Bill
Fedora 10, Gnome 2.24.3
Evo.2.24.5, Emacs 22.3.1