I have a help file for my app., it works fine when i´m the form designer, but it doesn't work when my application is running.

I have this in myapp.prg
set help to contab
***

In my form i have this:
set topic to "Maestro de cuentas"
***

I repeat, it works fine (shows the topic 'Maestro de cuentas')when i´m running from the from designer, but not in running time.

What can i do?