Use of uninitialized value in hash element at D:\scripts\whois.pl 
line 21, <FILE> line 1.

##</code><code>##

#Program used to get an ip address via a whois query using the 
clwhois tool

use strict;
use warnings;


my $cmd = 'd:\clwhois.exe';
my $ip = '192.168.1.1';
my $file = 'd:\temp\output.txt';

my ($email, %fields);

system("$cmd $ip >$file")
   and warn "Can not execute $cmd: $!\n";

open (FILE, $file) or die "Can not open $file: $!\n";

while (<FILE>){
  /^(.*?): \s*(.*)$/;    # Save text before colon in $1, and after 
                         # colon in $2 - Taken from the Camel Chp. 5.9
  $fields{$1} = $2;      # Creat %fields hash

}

# Save email address to $email depending on the whois db being used

if ($fields{"TechEmail"} ne ""){
   $email = $fields{"TechEmail"};
}
elsif ($fields{"e-mail"} ne ""){
   $email = $fields{"e-mail"};
}

print "Email is $email\n";