use strict;
use warnings;

use WWW::Mechanize;
my $m = WWW::Mechanize->new( autocheck => 1 );
$m->get("https://www.bittorrent.com/account/signin");

$m->submit_form(
      form_number => 2,
      fields      => {
         username    => 'mungo',
         password    => 'lost-and-alone',
      }
);

print $m->content;