diff --git a/Kernel/Controller.php b/Kernel/Controller.php
index 1e93190..d86cd25 100644
--- a/Kernel/Controller.php
+++ b/Kernel/Controller.php
@@ -55,11 +55,11 @@ final class controller
     public function execute()
     {
         if (!class_exists($this->_A_urlParts['controller'])) {
-            throw new ControllerException("Controller " . $this->_A_urlParts['controller'] . " is not valid.");
+            throw new NotFoundException("Controller " . $this->_A_urlParts['controller'] . " is not valid.");
         }
 
         if (!method_exists($this->_A_urlParts['controller'], $this->_A_urlParts['action'])) {
-            throw new ControllerException("Action " . $this->_A_urlParts['action'] . " of controller " .
+            throw new NotFoundException("Action " . $this->_A_urlParts['action'] . " of controller " .
                 $this->_A_urlParts['controller'] . " is not valid.");
         }
 
diff --git a/Kernel/Exceptions/NotFoundException.php b/Kernel/Exceptions/NotFoundException.php
new file mode 100644
index 0000000..d5a4600
--- /dev/null
+++ b/Kernel/Exceptions/NotFoundException.php
@@ -0,0 +1,3 @@
+<?php
+
+class NotFoundException extends Exception {}
diff --git a/index.php b/index.php
index 5f36be7..9426498 100644
--- a/index.php
+++ b/index.php
@@ -16,6 +16,8 @@
 
     View::openBuffer();
 
+    $ret = Utils::RETURN_HTML;
+
     try
     {
         $O_controller = new Controller($S_url, $A_postParams, $A_getParams);
@@ -23,19 +25,18 @@
     }
     catch (ControleurException $O_exception)
     {
-        echo ('An error occured: ' . $O_exception->getMessage());
+        View::openBuffer();
+        View::show("errors/500", $O_exception->getMessage());
+    }
+    catch (NotFoundException $O_exception)
+    {
+        View::openBuffer();
+        View::show("errors/404");
     }
     catch (HTTPSpecialCaseException $O_exception)
     {
-        // drop old buffer
-        View::closeBuffer();
         View::openBuffer();
-
         View::show("errors/".$O_exception->getHTTPCode(), $O_exception->getMsg());
-
-        $content = View::closeBuffer();
-        View::show('html', array('body' => $content));
-        return;
     }