public string Serialize()
{
string xml = "";
if (authenticationValue != null) xml += "\r\n<authenticationValue>" + SecurityElement.Escape(authenticationValue) + "</authenticationValue>";
if (authenticationTransactionId != null) xml += "\r\n<authenticationTransactionId>" + SecurityElement.Escape(authenticationTransactionId) + "</authenticationTransactionId>";
if (customerIpAddress != null) xml += "\r\n<customerIpAddress>" + SecurityElement.Escape(customerIpAddress) + "</customerIpAddress>";
if (authenticatedByMerchantSet) xml += "\r\n<authenticatedByMerchant>" + authenticatedByMerchantField + "</authenticatedByMerchant>";
return xml;
}