If you got to this bit, it means that we received an event we don't know 
about.  Time for you to brush up on your ARexx skills and add more :) 
 
  1        otherwise 
  2          nop 
  3        end 
  4 
  5      lister set handle busy off 
  6      call reply(packet,0) 
  7      end 
  8    end 
  9  end 
 
Line: 
 1 - 3  The Otherwise statement in the Select...When conditional block, we 
        received an event we didn't recognise, so we do nothing. 
 5      Turn off the busy state of the lister. 
 6      Reply to the message packet we received, YOU MUST DO THIS!!!! 
 7 - 9  End of 'if packet...'. 
        End of 'if waitpkt...'. 
        End of 'do until...'.