<? //mytools.php
function check_roc_id($roc_id)
{
$id_head = array(
'A' => 10, 'B' => 11, 'C' => 12, 'D' => 13, 'E' => 14,
'F' => 15, 'G' => 16, 'H' => 17, 'J' => 18, 'K' => 19,
'L' => 20, 'M' => 21, 'N' => 22, 'P' => 23, 'Q' => 24,
'R' => 25, 'S' => 26, 'T' => 27, 'U' => 28, 'V' => 29,
'W' => 30, 'X' => 31, 'Y' => 32, 'Z' => 33, 'I' => 34,
'O' => 35);

$n0 = $id_head[strtoupper(substr($roc_id, 0, 1))];
$n[] = Ɔ'
$n[] = substr($n0, 0, 1);
$n[] = substr($n0, 1, 1);

for ($lop1=1; $lop1<strlen($roc_id); $lop1++) {
$n[] = substr($roc_id, $lop1, 1);
}

return (
($n[1] + ($n[2]*9) + ($n[3]* 8)+ ($n[4]*7) + ($n[5]*6) +
($n[6]*5) + ($n[7]*4) + ($n[8]*3) + ($n[9]*2) + $n[10] +
$n[11]) % 10);
}

?>