Joe,
If there's an error I'd just set _screen.Visible = .t. and ? the usage info. Use a minimal menu that just has File/Exit. If you really want a dos box, build a .BAT on the fly and RUN it.
> i am writing a Console app with no main window or forms normaly. If the parameters are correct I want it to just execute the program without any user feedback. Otherwise I want to display to the dos box a classic USAGE: message or open a GUI.