Indicates that no problems were encountered and DSPINSTL
should proceed forward.
0xFFFFFFFF
Indicates that the action routine is
returning a Cancel indication, which might be triggered by the user pressing
a Cancel push button within a PM panel that was invoked by the action
routine. Note that the Cancel return code is supported so that DSPINSTL
can back out of its current execution path.
0xFFFFFFFE
Is a reserved return code
All
other non-zero values are interpreted as OS/2 system error codes.