diff --git a/src/Silex/Controller/FrontController.php b/src/Silex/Controller/FrontController.php
index 747c1ca..0443b56 100644
--- a/src/Silex/Controller/FrontController.php
+++ b/src/Silex/Controller/FrontController.php
@@ -10,15 +10,18 @@ use Silex\Router\Route;
 
 class FrontController
 {
-    private Route $route;
+    private ?Route $route;
 
-    public function __construct(Route $route)
+    public function __construct(?Route $route)
     {
         $this->route = $route;
     }
 
     public function run(DI $di): HttpResponse
     {
+        if ($this->route === null) {
+            return new HttpResponse(404, 'errors', ['errors' => ['Route not found']]);
+        }
         if ($this->route->getController() instanceof AdminController
             && ($di->getSecurity()->getCurrentUser() === null || !$di->getSecurity()->getCurrentUser()->isAdmin())) {
             HttpResponse::redirect($di->getRouter()->url('login'));
diff --git a/src/Silex/Controller/VisitorController.php b/src/Silex/Controller/VisitorController.php
index f9425c2..6f27520 100644
--- a/src/Silex/Controller/VisitorController.php
+++ b/src/Silex/Controller/VisitorController.php
@@ -9,6 +9,7 @@ use Silex\DI\DI;
 use Silex\Http\HttpResponse;
 use Silex\Model\Comment;
 use Silex\Util\Pagination;
+use Silex\Validation\CommentValidation;
 
 class VisitorController {
 
@@ -37,6 +38,9 @@ class VisitorController {
     {
         $newsId = intval($params['id']);
         $news = $di->getNewsGateway()->getById($newsId);
+        if ($news === null) {
+            return new HttpResponse(404, 'errors', ['errors' => ['Unknown news']]);
+        }
         if ($news->getSlug() !== $params['slug']) {
             HttpResponse::redirect($di->getRouter()->url($news->getSlugRedirect()));
         }
@@ -44,12 +48,19 @@ class VisitorController {
         return new HttpResponse(200, 'newsView', ['news' => $news, 'comments' => $comments]);
     }
 
-    public function comment(DI $di, array $params): void
+    public function comment(DI $di, array $params): HttpResponse
     {
         $newsId = intval($params['id']);
         $news = $di->getNewsGateway()->getById($newsId);
-        $comment = new Comment(-1, $newsId, new DateTime(), $_POST['content']);
+        if ($news === null) {
+            return new HttpResponse(404, 'errors', ['errors' => ['Unknown news']]);
+        }
         $author = $di->getSecurity()->getCurrentUser();
+        $errors = [];
+        if (!CommentValidation::isValidComment($_POST, $author === null, $errors)) {
+            return new HttpResponse(400, 'errors', ['errors' => $errors]);
+        }
+        $comment = new Comment(-1, $newsId, new DateTime(), $_POST['content']);
         if ($author !== null) {
             $comment->setAuthor($author);
         } else {
@@ -58,5 +69,6 @@ class VisitorController {
         }
         $di->getCommentGateway()->insert($comment);
         HttpResponse::redirect($di->getRouter()->url($news->getSlugRedirect()));
+        exit();
     }
 }
diff --git a/src/Silex/Gateway/NewsGateway.php b/src/Silex/Gateway/NewsGateway.php
index c7d28bf..e2ffda5 100644
--- a/src/Silex/Gateway/NewsGateway.php
+++ b/src/Silex/Gateway/NewsGateway.php
@@ -65,7 +65,7 @@ class NewsGateway
         return intval($req->fetch()['nb']);
     }
 
-    public function getById(int $id): News
+    public function getById(int $id): ?News
     {
         $req = $this->pdo->prepare('SELECT * FROM news WHERE id_news=:id;');
         $req->bindValue(':id', $id, PDO::PARAM_INT);
@@ -73,8 +73,7 @@ class NewsGateway
             return null;
         }
         $data = $req->fetch();
-        $news = $this->createNews($data);
-        return $news;
+        return $data === false ? null : $this->createNews($data);
     }
 
 
diff --git a/src/Silex/Http/HttpResponse.php b/src/Silex/Http/HttpResponse.php
index 41433f6..bde266f 100644
--- a/src/Silex/Http/HttpResponse.php
+++ b/src/Silex/Http/HttpResponse.php
@@ -35,6 +35,7 @@ class HttpResponse
 
     public function render(DI $di, string $viewBasePath)
     {
+        http_response_code($this->status);
         $router = $di->getRouter();
         $security = $di->getSecurity();
         $params = $this->viewParams;
diff --git a/src/Silex/Router/RouteNotFoundException.php b/src/Silex/Router/RouteNotFoundException.php
deleted file mode 100644
index e6c8f9f..0000000
--- a/src/Silex/Router/RouteNotFoundException.php
+++ /dev/null
@@ -1,20 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace Silex\Router;
-
-use Exception;
-use Throwable;
-
-/**
- * Lorsqu'aucune route ne correspond à l'url demandée.
- */
-class RouteNotFoundException extends Exception
-{
-
-	public function __construct(string $message, int $code = 0, ?Throwable $previous = null)
-	{
-		parent::__construct($message, $code, $previous);
-	}
-}
diff --git a/src/Silex/Router/Router.php b/src/Silex/Router/Router.php
index 282bcf6..8be3039 100644
--- a/src/Silex/Router/Router.php
+++ b/src/Silex/Router/Router.php
@@ -67,14 +67,14 @@ class Router
     public function run(DI $di): HttpResponse
     {
         if (!isset($this->routes[$_SERVER['REQUEST_METHOD']])) {
-            throw new RouteNotFoundException('Unknown HTTP method');
+            return (new FrontController(null))->run($di);
         }
         $url = $this->url;
         if ($this->basePath !== '') {
             if (PathHelper::startsWith($url, $this->basePath)) {
                 $url = trim(substr($url, strlen($this->basePath)), '/');
             } else {
-                throw new RouteNotFoundException('No matching routes');
+                return (new FrontController(null))->run($di);
             }
         }
         foreach ($this->routes[$_SERVER['REQUEST_METHOD']] as $route) {
@@ -82,6 +82,6 @@ class Router
                 return (new FrontController($route))->run($di);
             }
         }
-        throw new RouteNotFoundException('No matching routes');
+        return (new FrontController(null))->run($di);
     }
 }
diff --git a/src/Silex/Validation/CommentValidation.php b/src/Silex/Validation/CommentValidation.php
new file mode 100644
index 0000000..b410175
--- /dev/null
+++ b/src/Silex/Validation/CommentValidation.php
@@ -0,0 +1,17 @@
+<?php
+
+namespace Silex\Validation;
+
+final class CommentValidation
+{
+    public static function isValidComment(array $post, bool $requiresName, array &$errors): bool
+    {
+        if ($requiresName) {
+            UserValidation::isValidName($post, $errors, 'name');
+        }
+        if (empty($post['content'])) {
+            $errors[] = 'Empty message';
+        }
+        return empty($errors);
+    }
+}
diff --git a/src/Silex/Validation/UserValidation.php b/src/Silex/Validation/UserValidation.php
index b89f0f4..12ec20a 100644
--- a/src/Silex/Validation/UserValidation.php
+++ b/src/Silex/Validation/UserValidation.php
@@ -6,24 +6,18 @@ namespace Silex\Validation;
 
 final class UserValidation
 {
-    public static function isValidLogin(array &$post, array &$errors): bool
+    public static function isValidLogin(array $post, array &$errors): bool
     {
-        if(empty($post['login'])) {
-            $errors[] = 'Login error';
-        }
-
+        self::isValidName($post, $errors);
         if(empty($post['password'])) {
             $errors[] = 'Password error';
         }
         return empty($errors);
     }
 
-    public static function isValidUser(array &$post, array &$errors): bool
+    public static function isValidUser(array $post, array &$errors): bool
     {
-        if(empty($post['login'])) {
-            $errors[] = 'Login empty error';
-        }
-
+        self::isValidName($post, $errors);
         if(empty($post['password'])) {
             $errors[] = 'Password empty error';
         }
@@ -38,4 +32,14 @@ final class UserValidation
 
         return empty($errors);
     }
+
+    public static function isValidName(array $post, array &$errors, string $key = 'login'): bool
+    {
+        if(empty($post[$key])) {
+            $errors[] = 'Empty login';
+        } else if(strlen($post[$key]) > 32) {
+            $errors[] = 'Login too long';
+        }
+        return empty($errors);
+    }
 }
diff --git a/views/errors.php b/views/errors.php
index ee44fac..a06afbb 100644
--- a/views/errors.php
+++ b/views/errors.php
@@ -1,11 +1,12 @@
-<?php if ($params['errors']) : 
-	foreach ($params['errors'] as $error) { ?>
-    <article class="message is-danger">
-        <div class="message-header">
-            <p>Auth failed</p>
-        </div>
-        <div class="message-body">
-            <?= $error?>
-        </div>
-    </article>
-<?php } endif ?>
+<?php if ($params['errors']):
+    foreach ($params['errors'] as $error): ?>
+        <article class="message is-danger">
+            <div class="message-header">
+                <p>Error</p>
+            </div>
+            <div class="message-body">
+                <?= $error ?>
+            </div>
+        </article>
+    <?php endforeach;
+endif; ?>