VIEW /OVERLAY

        [DISPLAY\]VIEW Argument [First [Last]] /OVERLAY [Variable [Channel]]
     [/DIRECTORY NameTree] [/NOPAUSE]

    Overlay  (in  contours)  the specified Channel of the specified SIC 2 or 3-D
    Variable.  The default Variable is CONTINUUM, the continuum image. If  Vari-
    able  is  a 3-D SIC Variable, Channel indicates which plane is overlaid (de-
    fault: last one).

    In addition to this overlay, the user can add any display  on  the  two  map
    plots  (current  channel  and integrated area) by specifying a command to be
    executed through the OVERLAY_COM variable.  This command can be  the  execu-
    tion of a script, e.g.
              LET OVERLAY_COM "@ draw_my_markers"
    or
              LET OVERLAY_COM "@ p_beam clean"
    to plot the clean beam.

    Note that this variable is not defined by default, so must be defined
              DEFINE Char*80 OVERLAY_COM /GLOBAL
    when needed