Perl error - uninitialized value has me stumped

[BradK]

I'm getting an error that I can't figure out.

I'm sending this at the address line:
http://www.lcni2.com/cgi/adhey5.cgi?hey

Expecting to see:
You entered: hey

Instead I get:
You entered:

The error log says:
Tue Apr 10 12:04:08 2007] adhey5.cgi: Use of uninitialized value in concatenation (.) or string at /home/content/l/c/n/lcnimaster/html/cgi/adhey5.cgi line 18.


CHMOD is set to 777 and the script is:
#!/usr/bin/perl -T -w

use strict;
use CGI ':standard';
use CGI::Carp 'fatalsToBrowser';

print "Content-type: text/html\n\n";

my $ARGV;
my $hey;
my $hey1;
my $hey2;



$hey2 = $ARGV[0];
$hey1 = "You entered: ";
$hey = "$hey1 $hey2";

print $hey;

exit;


Any help would be hugely appreciated!!!

Thanks,
Brad