use HTTP::Cookies;
use LWP;

$cookie_jar = HTTP::Cookies->new (
                file => "cookie_jar.lwp",
                autosave => 1,
                );

$ua= LWP::UserAgent->new;
$ua->cookie_jar( $cookie_jar );

$ua->agent("Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.6) Gecko/20050317 Firefox/1.0.2");

my $req = HTTP::Request->new(POST => 'http://www.perlmonks.com/');
$req->content_type('application/x-www-form-urlencoded');
$req->content('node_id=131&op=login&user=Adrade&passwd=pass-goes-here&expires=%2B10y&login=Login');

my $res = $ua->request($req);

print $cookie_jar->as_string;