mixed language help needed

[Juan Nastri]

Hello,
I am writing a new main for an old program written in fortran and I am
looking for a light somewhere.
The general idea is to use the old fortran subroutines, and make the new
main in plain C.
I have read a lot of pages, speaking about mixed language, and a lot of
different things where suggested.
But what I need is quite simple.  I need a concrete example on how to
link a subroutine.f with a main_program.c.
Lets say, that the subroutine uses 2 integer as a parameters.
Exactly what should I tell to gcc and g77 to correctly compile this??
and example of a makefile would be usefull too!

Thank you at least to read this.  If you can help me, I would be very
happy.
Juan
Ps. Please, forgive my poor english, is not my natural language.