ho riscritto il codice come hai detto tu,
<?
//Recupero username e password dal form
$user = $_POST['user'];
//Apro la sessione e...
session_start();
//Salvo i dati...
$_SESSION['id_user'] = $id_user;
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<title>Documento senza titolo</title>
</head>
<body>
<?php
$connessione=mysql_connect("localhost", "");
$selezione_db=mysql_select_db("guest_book", $connessione);
?>
<?php
$inserimento=mysql_query( "insert into messaggi (user, gender, date_of_birth,country, data_ora) values ( '" . $_POST['user'] . "','" . $_POST['gender'] . "','" . $_POST['year'] . "-" . $_POST['month'] . "-" . $_POST['day'] . "', '" . $_POST['country'] . "', now())" );
?>
<?php
$sid = session_name() . '=' . session_id();
session_write_close();
header("Location: <a href="http://localhost/test2.html?" target="_blank"http://localhost/test2.html?</a>$sid");
?>
</body>
</html>
pero' adesso mi da questo errore:
Parse error: parse error in c:\programmi\easyphp1-8\www\elabora_guest2.php on line 36
LINEA 36:
header("Location: <a href="http://localhost/test2.html?" target="_blank"http://localhost/test2.html?</a>$sid");
?>