Aggiunto messaggio errore in pagina login

login.php

@@ -49,7 +49,11 @@
         <label for="email">Indirizzo e-mail:</label>
         <input type="email" id="email" name="email" required><br>
         <label for="password">Password:</label>
-        <input type="password" id="password" name="password" required><br><br>
+        <input type="password" id="password" name="password" required><br>
+        <?php if ($error): ?>
+            <p style="color: red; text-align: center;"><?php echo htmlspecialchars($error); ?></p>
+        <?php endif; ?>
+        <br>
         <button type="submit">Login</button>
         <p style="text-align: center;">Non hai un account? <a href="register.php">Registrati</a></p>
     </form>