Version 3.0 of VMake implements an interactive mode for Rexx commands.

There is a new command, REXXI, that can be called with a parameter value
of either "ON" or "OFF".  Any other parameter will cause VMake to issue
a requester that uses a new TEXT slot (position 23) complaining about an
invalid Rexx Interactive mode:

TEXT "23" "Invalid REXX Interactive mode: "

In the default state ("OFF"), VMake functions as it always has.  When a 
command is invoked from REXX, if it tries to invoke any kind of requester
the command will abort and return a non zero code to via Rexx.  This is
intended to allow background operation from REXX.

If the Rexx state is "ON", requesters are allowed, and no return code is
set.  This mode is intended to allow you to enhance the commands available
with VMake, eg to write scripts to be invoked by buttons or menus.

There is also a new system symbol, _REXXINTER_ which will return the last
value set by a valid REXXI command to VMake.  It starts out set to OFF.
You can check this symbol at the start of a Rexx script by using the LOG
command and then issue another REXXI command at the end of your script to
restore the original setting.  Directly setting _REXXINTER_ will not change
the Rexx processing mode, you must use the REXXI command.

(Note to JAT: I did it that way because directly setting the symbol would
also set the dirty flag, which is inappropriate, and it's easier to check
for valid values in a command than in the general SET command.)