public static function asc2hex32($string)
    {
        for ($i = 0; $i < strlen($string); $i++) {
            $char = substr($string, $i, 1);
            if (ord($char) < 32) {
                $hex = dechex(ord($char));
                if (strlen($hex) == 1) $hex = '0'.$hex;
                $string = str_replace($char, '\\'.$hex, $string);
            }
        }
        return $string;
    }