Perl Proxy Judge

#!/usr/bin/perl

##############################################
# Copyright (c) by Hell labs Team, 2001-2005 #
##############################################

print "Content-type: text/plain; charset=us-ascii\r\n\r\n";
print "REMOTE_ADDR=$ENV{'REMOTE_ADDR'}\r\n";
$nora=0;
if($ENV{'HTTP_X_FORWARDED_FOR'} eq $ENV{'REMOTE_ADDR'})
{
 $nora=1;
}
foreach (sort keys %ENV)
{
    if(!($_ eq 'HTTP_X_FORWARDED_FOR')||($nora==0))
    {
        print "$_=$ENV{$_}\r\n";
    }
}
exit;