RoyK

    function macfmt($s) {        if (preg_match('/^([\da-z]{2})([\da-z]{2})([\da-z]{2})([\da-z]{2})([\da-z]{2})([\da-z]{2})$/i', $s, $m))            $retstr = $m[1] . ":" . $m[2] . ":" . $m[3] . ":" . $m[4] . ":" . $m[5] . ":" . $m[6];        else            $retstr = $s;        return strtolower($retstr);    }