Perl - send form POST (See related posts)

use HTTP::Request::Common qw(POST);
use LWP::UserAgent;

my $user = "user";
my $pass = "pass";

my $browser = LWP::UserAgent->new();

my $responde = HTTP::Request->new(POST => "http://www.sito.com/index.php");
$responde->content_type("application/x-www-form-urlencoded");
$responde->content("user=" . $user . "&pass=" . $pass);

$browser->request($responde)->as_string