>Ed,
>
>Thanks for the explanation. I'll have to create a DLL and try some of this stuff. What you're saying is a lot different than what is described in the help for DECLARE. You think you understand something...
>

Actually, you can use existing Win32 API calls that pass things by ref and by value to see the various effects. No need to write something just to test it - the WinAPI section contains a few dozen API declarations for VFP that include both byref and byval parameters to play with.