What I want it to send back is the normal 404 error page for the particular web browser that you are using.

The 404 Error page is not determined by a browser, it's done at the server level. You can cutomize your 404 error page to say whatever you want it to. See this page for details on how to do this with Apache.

If you want to do this in your code you'll want to do something like the following.

#!/bin/perl

use strict;
use warnings;

sub NotFound { return '404'; }

use CGI::Pretty;
use CGI::Carp qw(fatalsToBrowser);
$CGI::Pretty::INDENT = '  ';

my $WP = new CGI::Pretty;
print $WP->header(-status => &NotFound), 
      $WP->h1("404 Page Not Found");
[download]