open file versus launch commands

[Stgoldberg at aol.com]

Thanks to James for the advice to try to use the "launch" command rather than 
the "open file" command to open a file in the same folder as the Revolution 
application.   The launch command does work on opening an application but only 
after the Revolution program has been built as a standalone.   Am I correct in 
that   one needs to first build a standalone for the launch command to work?  
 Also, when should the "open file " command be used as opposed to the launch 
command?   Thanks.   
Steve Goldberg