monitor crosses into subroutines

Don't know if it's good or bad, but seems that monitor crosses into 
subroutines.  Got some old code bringing up to date and I put in:
     C                   monitor
     C                   eval      opt#=%dec(%trim(cmd):LenOpt#:DecOpt#)
     C                   exsr      MENU#
     C                   eval      cmd=*blanks
     C                   On-Error
     C*                    // Not numeric
     C                   EndMon
Basically, it was a homegrown menu system.  If the entry was numeric go 
process the subroutine.  (I will probably use %int because of recent 
emails to this list.)  Anyway, if it's processing the subroutines MENU# 
and an error occurs, it jumps out of the subroutine and right into the 
On-Error.  Took me several times through debug before I figured that out. 
Kept thinking my source was out of sync with my code.

You know, I use subprocedures so much that every time that I starting 
typing subroutines for this email I started typing subprocedures and had 
to backup and fix it.  :-)

Rob Berendt