open FOO, "<$foo" or fatalerror "Couldn't Read Foo: $!";
  # and off in an include file somewhere I define...
sub fatalerror {
  my $email = $ENV{SERVER_ADMIN};
  use HTML::Entities;
  my $code = encode_entities(shift);
  my $fm = <<"FRIENDLYMESSAGE";
  <p class=\"error\">Oops!  I seem to have run
     into a problem!  This is probably a bug
     in the software on this site, something
     that the webmaster needs to fix.  If
     this problem persists, you can contact the
     webmaster at <a href="mailto:$email">$email</a>
     and report the problem.  It might get fixed
     faster if you include the exact technical
     error code that follows.
  </p>
  <p class=\"error\">Technical Error Code: $code</p>
FRIENDLYMESSAGE
  # And then I output a page containing $fm in the
  # usual fashion.
}