diff --git a/authentication.php b/authentication.php
index 5c9d301..c451038 100644
--- a/authentication.php
+++ b/authentication.php
@@ -29,7 +29,10 @@ class authentication
   /** The rest authentication methods. Can be http, session, post.
       Attention : session case = CSRF ! */
   public $restMethods = array ("http");
-  /** The html authentication methods. Can be http, session, post */
+  /** The html authentication methods. Can be http, session, post
+    * The "post" is already used when using verifAuthLoginPage method (usually
+    * only in authentication page)
+    */
   public $htmlMethods = array ("session");
   /** The authentication methods. Can be ldap, sympa...*/
   public $authMethods = array ();
@@ -346,8 +349,8 @@ class authentication
     */
   private function logging ($priority, $message)
   {
-    if ($priority > 4)
+    if ($this->debug === 0 && $priority > 4)
       return;
-    echo "$priority : $message\n";
+    file_put_contents ("/tmp/auth.log", "$priority : $message\n", FILE_APPEND);
   }
 }