I have some code to "massage" my client's customer billing statement VFP data into a CSV file which is then manually uploaded into Authorize.net via their web-based forms.
That's the approach that the client wanted to use for now until it is proven to work reliably. And it has worked well for 2 uploads per month for the past 3 months now.
My client initially worked with the Authorize.net using their web-based forms to map their data. I then use that user-defined map to create the CSV file. It is really a pretty simple process.
After the information is processed, Authorize.net allows a user to manually download (via their web-based forms) a post-transaction text file.
I also have a routine to process it back into VFP data which can then be recorded into the client's Customer AR Journal.
Again a pretty simple process.
The long range goal would be to FTP the files in both directions, but the client hasn't been willing to take that step yet and, consequently, we have not explored it with Authorize.net yet.
If someone else has the FTP side of the Authorize.net stuff working, I'd also be interested in hearing about it. Baring security issues (logon's, etc.), I don't imagine that it would be too difficult.
Good Luck,
JRB-Bldr