Création d'un espace de chat

CREATE TABLE `minichat` (
  `id` int(32) NOT NULL auto_increment,
  `pseudo` varchar(32) collate latin1_general_ci NOT NULL,
  `message` varchar(255) collate latin1_general_ci NOT NULL,
  `heure` timestamp NOT NULL default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP,
  PRIMARY KEY  (`id`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 COLLATE=latin1_general_ci AUTO_INCREMENT=39 ;

<form action="minichat_post.php" method="POST">
                <p>
                Pseudo : <br/><input type="text" value="<?php echo $_COOKIE['pseudo1']; ?>" name="pseudo" id="pseudo" /><br />
                Message : <br/><textarea name="message" rows="5" cols="30" id="message"></textarea><br />

                <input type="submit" value="Envoyer"/>
                </p><br>
                <hr>
                </form>
                <?php
                define("NOM","login_db_SQL");       
                  define("PASSE","mot_de_passe_db_SQL");
                  define("SERVEUR","adresse_serveur_SQL");
                  define("BASE","nom_db_SQL");      

                //--Connexion au serveur
$link = mysql_connect(SERVEUR,NOM,PASSE);

if(!$link) {echo"Impossible de se connecter au serveur".mysql_error();exit;}
//--Connexion à la base
mysql_select_db(BASE,$link);


$requete= "SELECT * FROM minichat";

$reponse = mysql_query("SELECT * FROM minichat ORDER BY id DESC LIMIT 0,10");

while($r=mysql_fetch_array($reponse, MYSQL_ASSOC))
    {echo"<i><b style='font-size:10px;'>$r[heure]</b></i><br><b>$r[pseudo]:</b> $r[message]<br><br>";
    
    } 

mysql_close($link);

                ?>

<?php
    ob_start();
?>
<?php
$pseu = htmlspecialchars($_POST['pseudo']);
setcookie('pseudo1', $pseu, time() + (86400 * 30), "/");
$msg = htmlspecialchars($_POST['message']);
define("NOM","login_db_SQL");       
                  define("PASSE","mot_de_passe_db_SQL");
                  define("SERVEUR","adresse_serveur_SQL");
                  define("BASE","nom_db_SQL");    
                //--Connexion au serveur
$link = mysql_connect(SERVEUR,NOM,PASSE);

if(!$link) {echo"Impossible de se connecter au serveur".mysql_error();exit;}
else {echo"connection au serveur réussie !";}

//--Connexion à la base
mysql_select_db(BASE,$link);
$requete= "INSERT INTO minichat SET pseudo='$pseu', message='$msg' ";

mysql_query($requete, $link) or die("Echec d'insertion".mysql_error());

mysql_close($link);
echo '<script language="Javascript">
<!--
document.location.replace("url_index");
// -->
</script>';
?>
<?php
    ob_end_flush();
?>