public static function formatMacAddress($validAddress)
    {
        if (strlen($validAddress) == 12) {
            $formattedAddress = substr($validAddress, 0, 2);
            for ($i=2; $i<12; $i+=2) {
                $formattedAddress .= ':'.substr($validAddress, $i, 2);
            }
            return $formattedAddress;
        }
        if (strlen($validAddress) == 17) {
            $formattedAddress = str_replace('-', ':', $validAddress);
            return $formattedAddress;
        }
    }