//Validates IMEI checksum
function valideteImeiChecksum(imei) {
    len = imei.length - 1;
    digit = new Array;
    cnt = 15;
    even = 0;
    odd = 0;
    for (i = 0; i < len; i++) {
        cnt--;
        if (cnt % 2) {
            digit[cnt] = 2 * parseInt(imei.substr(i, 1));
            if (digit[cnt] > 9) {
                even += parseInt(digit[cnt] / 10) + digit[cnt] % 10;
            } else {
                even += parseInt(digit[cnt]);
            }
        }
        else {
            digit[cnt] = parseInt(imei.substr(i, 1));
            odd += parseInt(imei.substr(i, 1));
        }
    }
    sum = even + odd;
    if ((sum % 10) == 0) {
        end_digit = 0;
    }
    else {
        _sum = "" + sum;
        end_digit = (parseInt(_sum.substr(0, 1)) + 1) * 10 - sum;
    }
    if (end_digit == imei.substr(14, 1)) {
        return 1;
    }
    else {
        return 0;
    }
}