public string Serialize()
{
string xml = "";
if (prepaidSet) xml += "\r\n<prepaid>" + prepaidField.ToString().ToLower() + "</prepaid>";
if (internationalSet) xml += "\r\n<international>" + internationalField.ToString().ToLower() + "</international>";
if (chargebackSet) xml += "\r\n<chargeback>" + chargebackField.ToString().ToLower() + "</chargeback>";
return xml;
}