static function set($key, $value, $class = '')
 {
     $con = Doctrine_Core::getConnectionByTableName('Registry');
     $con->beginTransaction();
     try {
         $reg = Doctrine_Core::getTable('Registry')->createQuery('r')->where('r.regkey = ?', $key)->fetchOne();
         if (!$reg) {
             $reg = new Registry();
             $reg->setRegkey($key);
         }
         $reg->setRegclass($class);
         $reg->setValue($value);
         $reg->save();
         $con->commit();
         return true;
     } catch (Exception $e) {
         $con->rollback();
     }
     return false;
 }