static void Main(string[] args) 
 {
   Transaction transaction = new Transaction();
   transaction.Environment = "TEST";
   
   ResponseBase response = transaction.Void(
     "100", // 'merchantId' - REQUIRED: Merchant ID assigned by maxiPago!  //
     "merchant-key", // 'merchantKey' - REQUIRED: Merchant Key assigned by maxiPago! //
     "293823", // 'transactionID' - REQUIRED: Transaction ID created by maxiPago! //
     "127.0.0.1" // 'ipAddress' - Optional //
   );
   
   if (response.IsTransactionResponse)   {
     TransactionResponse result = response as TransactionResponse;
   
     if (result.ResponseCode == "0")  {
       // Success
     }
     else { 
       // Declined
     }
   }
   else if (response.IsErrorResponse)   {
     ErrorResponse result = response as ErrorResponse;
     // Fail
   }
 }