SmartPos - External Transaction
-------------------------------
https://connectpayadmin.co.uk/services/smartpos2/Http/ExternalTransaction.ashx?Function=XXX&Format=...

FUNCTION: ADD
- Format: JSON, XML, QueryString
- Account: Adelante Account ID
- User: Adelante User Name
- Password: Adelante Password
- Date: Transaction Date
- OrderReference: Order Reference
- CustomerReference: Customer Reference
- FundCode: Fund Code
- Amount: Amount In PENNIES
- CardNumber: Card Number - XX/XXXX
- Status: Authorised, Cancelled, DataError, Declined, SystemError, Unknown, Valid, Voided
- AuthCode: Auth Code
- TransactionNo: External Transaction No
- Key: Unique Key
- RefundID: MPOSID Of Original Transaction If Refund
RETURNS
- Result: 'OK' or 'Error Message'

FUNCTION: GET
- Format: JSON, XML, QueryString
- Account: Adelante Account ID
- User: Adelante User Name
- Password: Adelante Password
- MPOSID: MPOSID - Unique ID
RETURNS
- Result: 'OK' or 'Error Message'
- Status: Authorised, Declined, Etc.
- StatusValue: -1 = Unknown; 0 = Authorised; 1 = Declined; 2 = Data Error; 3 = System Error; 4 = Valid; 5 = Voided

FUNCTION: QUERY
- Format: JSON, XML, QueryString
- Account: Adelante Account ID
- User: Adelante User Name
- Password: Adelante Password
- Key: Unique Merchant Key
- OrderReference: *OR* Order Reference / Ref #
RETURNS
- Result: 'OK' or 'Error Message'

FUNCTION: REFUND
- Format: JSON, XML, QueryString
- Account: Adelante Account ID
- User: Adelante User Name
- Password: Adelante Password
- MPOSID: Transaction To Refund
- Amount: Amount in PENNIES
RETURNS
- Result: 'OK' or 'Error Message'