Betfair has an Exchange API and a Tote API. Code which accesses the Tote API has to perform login and logout functions via the Exchange API. Both APIs were formerly implemented using SOAP and we have what was a functioning module for the Tote API written using Visual Studio 2010 VB.Net.
The Exchange API, only, has now been replaced by one based on JSON rather than SOAP and we need to amend our module to make the appropriate login and logout calls though the meat of the program can remain unaltered. There is some sample code but the integration of JSON with VB.Net is where we need expertise.