weights: 6 5 7 2 3 4 5 6 7 digits: d1 d2 d3 d4 d5 d6 d7 d8 d9 d10 Here is algorithm for finding d10: sum = 6*d1+5*d2+7*d3+2*d4+3*d5+4*d6+5*d7+6*d8+7*d9 d10 = sum mod 11
for($i = 0; $i<10; $i++)
{
if(!($ni[$i]>='0' && $ni[$i]<='9')) {
print "Incorrect NIP! (DIGIT)<BR>";
return 1;
}
$arr[$i] = $ni[$i]-'0';
}
$sum = $arr[0]*6+$arr[1]*5+$arr[2]*7+$arr[3]*2+$arr[4]*3+$arr[5]*4+$arr[6]*5+$arr[7]*6+$arr[8]*7;
$sum %= 11;
if($sum==10) $sum=0;
if($sum!=$arr[9]) {
print "Incorrect NIP (code)!<BR>";
return 1;
}
print "CORRECT!<BR>Your NIP code is: $ni<br>";