code: def settle(self, reserveTransactionId, transactionAmount=None):
          
          params = {}
          params['ReserveTransactionId'] = reserveTransactionId
          if(transactionAmount != None):
              params['TransactionAmount'] = transactionAmount
          
          response = self.make_request("Settle", params)
          body = response.read()
          if(response.status == 200):
              rs = ResultSet()
              h = handler.XmlHandler(rs, self)
              xml.sax.parseString(body, h)
              return rs
          else:
              raise FPSResponseError(response.status, response.reason, body)
docs: Charges for a reserved payment.