Système private chat en PHP

if(isset($_SESSION['pseudo']) AND isset($_POST['message']) AND !empty($_POST['message'])){
  $pseudo = $_SESSION['pseudo'];
  $message = htmlspecialchars($_POST['message']);
  $req = $db->prepare('INSERT INTO [/contents/1315-chat chat] (pseudo, message) VALUES(?, ?)');
  $req->execute(array($pseudo, $message));
     $requser = $db->prepare("SELECT * FROM users WHERE id = ?");
     $requser->execute(array($_SESSION['pseudo']));
     $user = $requser->fetch();

}

?>
// Affichage des message
 <div id="message">
     	    <?php
               $allmsg = $db->query('SELECT pseudo, message, avatar FROM chat ORDER BY id DESC LIMIT 15');
                while($msg = $allmsg->fetch())
              {
            ?>
          
                <b><a href="profile.php?id=<?= find_user_by_id('user_id') ?>"><li class="list-group-item"> <img src="<?=  get_avatar_url($user->email) ?>" alt="<?= $user->pseudo ?>" class="avatar-xs"><?= $msg ['pseudo']; ?></a>: </b>     <l><?= $msg['message']; ?></l>
              <?php
              } 
          ?>
<form method="post" action="">
           	<br/>
           	<[/html/htmlform.php3 textarea] type="text" name="message" class="chat_dox"  rows="4" placeholder="Votre message" /></textarea><br/>
     	      <input type="submit" class="dox_custum" value="Envoyer" />
           </form>