Fast becoming one of my favorite new features in VFP 7 is the OF clause in DEFINE CLASS. Before this, you had to SET PROC TO SOME_OTHER_PRG before instanciating a subclass that is based on a class in a different PRG file.

Now all you have to do is:

DEFINE Class MySubClass as ParentClassName of PRG_FileName_Where_ParentClass_Is

No more SET PROC TO THE_OTHER_PRG_FILE