a golden oldie challenge: Eliza

Having got 3936 LOC through a 4000 LOC implementation, I thought I'd
do some recreational
hacking and do an old old program I've not looked at for some time -
Eliza.   You all know Eliza well enough for me not to have to spell it
out.  The challenge is to implement or dig up an Eliza program (you
don't have to write it yourself) in your favourite FPL.  Note that the
script that drives Eliza's responses should not be counted towards the
LOC count.  Some constraints.

1.  The script itself should be changeable by any novice.  That is to
say that it should not
     be a pile of hard-wired code written in the native language of
the program or require
     deep programming skills.

2.  The program should receive keyboard input from the user -
including the usual punctuation
     and any characters he wants to enter without crashing.

During the Harrop Wars on comp.lang.lisp a lot of stuff was thrown
around about the desirability of pattern matching.  The challenge is
interesting because it involves a style of pattern-matching called
'segment pattern matching' that is not hard-wired into most FPLs and
I'd like to see how well different FPLs cope with something outside
the standard.

Oh last thing; don't get too uptight about this.  It's only a bit of
fun.

Mark