public function serializeUploadFileExtensions($types)
    {
        $serialized = '';
        $types = preg_replace('{[^a-z0-9]}i', '', $types);
        foreach ($types as $type) {
            $serialized .= '*.'.$type.';';
        }
        //removing trailing ; unclear if multiupload will choke on that or not
        $serialized = substr($serialized, 0, strlen($serialized) - 1);

        return $serialized;
    }