As someone else said, their website is far more likely to help, I doubt most of us have ever used authorize.net, so how can we help you ? I would guess that the transaction key is the thing you need to get to be authorised to use the site, but I really have no idea.
Christian Graus - Microsoft MVP - C++ "I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )