Javascript NIB (Bank Identification Number) Validation

nibvalidator.js

function validateNIB(t, max_len)
{
    var pesos = [0, 1, 10, 3, 30, 9, 90, 27, 76, 81, 34, 49, 5, 50, 15, 53, 45, 62, 38, 89, 17, 73, 51, 25, 56, 75, 71, 31, 19, 93, 57],
        validateValue = t.toString(),
        s = validateValue.split(''),
        r = s.reverse(),
        tot = 0;

    if (t == undefined) {
        return false;
    }

    if (validateValue.length <= 0 || validateValue.length != max_len) {
        return false;
    }

    for (var i = 2; i < r.length; i++) {
        tot += r[parseInt(i)] * pesos[(parseInt(i)+1)];
    }

    var resto = (tot % 97),
        val = parseInt(98 - resto);

    if (val == parseInt(validateValue.substring((validateValue.length - 2)), 10)) {
        return true;
    } else {
        return false
    }
}