When I include a header file in a .prg the classes/forms I instantiate/call from this .prg don't know the defined variables in this header file.

ie I've got a simple prg like this:
#INCLUDE "myheader.h"
public oApp
oApp = createobject('customClass')


In the init event of oApp i've this code
? cMyConstant

cMyConstant is, of course, defined in myheader.h

I get an error Variable cMyconstant is not found or something like that.

I've studied tastrade but that didn't help.

What am i missing here???

tia, victor