function InsertFP ($loginid, $txnkey, $amount, $sequence, $currency = "") {
    $tstamp = time ();
    $fingerprint = $this->hmac ($txnkey, $loginid . "^" . $sequence . "^" . $tstamp . "^" . $amount . "^" . $currency);
    $security_array = array('x_fp_sequence' => $sequence,
                            'x_fp_timestamp' => $tstamp,
                            'x_fp_hash' => $fingerprint);
    return $security_array;
  }