function init($addDefaultLifetime)
 {
     parent::init();
     $lifetimes = array('-1' => 'Unbegrenzt', '60' => '1 Min', '300' => '5 Min', '900' => '15 Min', '1800' => '30 Min', '3600' => '1 Stunde', '14400' => '4 Stunden', '86400' => '1 Tag', '172800' => '2 Tage', '604800' => '7 Tage', '2678400' => '1 Monat');
     if ($addDefaultLifetime) {
         $lifetimes['0'] = 'Standard';
     }
     foreach ($lifetimes as $time => $label) {
         $this->add_option($label, $time);
     }
 }