How to use a forward function declaration in a program ?

[Michael de Estrada]

I know this must be obvious can't figure it out. I have a subroutine called by a main program that I want to move to the end of the end of the main program as follows:

EXPORT Sub1;

EXPORT Main_prog
Begin

Sub1;

End;

Sub1
Begin

End;

I'm getting a syntax error just before the Begin after the Sub1. What am I doing wrong?