Beginner's question about accept

[Scott McKay <SWM@sapsucker.scrc.symbolics.com>]

    Date: 23 Jun 88 12:34 +0100
    From: alberts%cui.unige.ch@RELAY.CS.NET (Gunter Albers)

    This is an example which shows how one could use icons.
    (It's not great code I know!)
    Now I have the problem that I don't know how to inhibit "accept"
    to print back an accepted value to window where it is read.
    (in the function do-it)        Any ideas ?

    I do not want to modify sys:print or the presentation type.

Why not?  Changing the printer for the p-t seems like the best place to
start.  Also, since you can't really ever type in icons, you should
probably make your parser just signal an error.