You sent me a bad thing:

#!/usr/bin/perl
##########################################################
# AGo    Version 1
# Copyright 2002 by Brian Benison www.bigandloud.com
#    TO CALL THIS PROGRAM:
#    /cgi-bin/AGo.cgi?1234567
# 
# the beginning of the URL (part BEFORE the bit sent to this CGI)
$mystart = 'http://www.amazon.com/exec/obidos/ASIN/';
# the end of the URL (part AFTER the bit sent to this CGI)
$myfinish = '/brianbenisonm-20';
# Where this script goes if a) the parameter sent is invalid and
# b) printstat is turned off
$defaultdest = 'http://www.amazon.com/exec/obidos/redirect-home/brianbenisonm-20';
$printstat = '0';
# (good) $mystart = 'http://www.';
# (good) $myfinish = '.com';
$string = $ENV{'QUERY_STRING'};
$countstat = '1';
$counterfile = "/www/b/benison/htdocs/AGoCounter.txt";
#########################
# First, add this execution of the CGI to the counter, 
# if countstat is turned on
if ($countstat) {
    open (COUNTER, "$counterfile");
    $count = <COUNTER>;
    chop ($count) if $count =~ /\n$/;
    close (COUNTER);
    # Increase Count
    $count += 1;
    open (COUNTER, ">$counterfile");
    print COUNTER ("$count");
    close (COUNTER);
}
#########################
# Just to be on the safe side, we'll only accept alphanumeric
# characters, so there'll be no tricky business.  If $printstat = '1',
# user will also see a page saying their query string was not accepted.
# If no string, then same deal.  (Mostly you'll want to set $printstat 
# for testing)
#########################
 if ($string eq '') {&error('is_blank')}
 if ($string =~ /[^a-zA-Z0-9]/) {&error('is_bad')}
#########################
# Now, back to business:
#########################
    $mydestination = "$mystart$string$myfinish";
    print "Location: $mydestination\n\n";
# 
sub error { 
#     Localize variable.
    local($error) = @_;
        if ($printstat) {
            print "Content-type: text/html\n\n";
            print "<html>\n <head></head>\n";
                if ($error eq 'is_bad') {
                    print "<title>You sent me a bad thing:</title>\n";
                }
                 if ($error eq 'is_blank') {
                     print "<title>You forgot to send a query expression!</title>\n";
                }
            print "$string\n\n";
            print "</html>\n";
        }
          else {print "Location: $defaultdest\n\n";
     }
   }
exit;