static public String nfc(float num, int right) {
    if ((float_nf != null) &&
        (float_nf_left == 0) &&
        (float_nf_right == right) &&
        float_nf_commas) {
      return float_nf.format(num);
    }

    float_nf = NumberFormat.getInstance();
    float_nf.setGroupingUsed(true);
    float_nf_commas = true;

    if (right != 0) {
      float_nf.setMinimumFractionDigits(right);
      float_nf.setMaximumFractionDigits(right);
    }
    float_nf_left = 0;
    float_nf_right = right;
    return float_nf.format(num);
  }