$post = "name=$name&mess=$mess&id=$id";
  $len = strlen($post);
  $query = "POST /go.php HTTP/1.1\r\n".
	 "User-Agent: Mozillko\r\n".
	 "Host: host.com\r\n".
	 "Referer: http://host.com\r\n".
	 "Content-Type: application/x-www-form-urlencoded\r\n".
	 "Connection: close\r\n".
	 "Content-Length: $len\r\n".
	 "\r\n".
	 "$post";

use LWP::UserAgent;
use HTTP::Request;
$url = "http://site.ru";
$ua = LWP::UserAgent->new();
$req = HTTP::Request->new (POST => $url);
$req->content_type ("application/x-www-form-urlencoded");
$req->content ("name=IMYA&message=MESSAGE&id=ID");
$res = $ua->request($req);
die "Error: " . $res->status_line unless ($res->is_success);
$content = $res->content;
....