XA Rel7 User Exit - total newbie question

[jfurniss]

Everyone, I've belonged to the list for some time but have never really had the need to post before. I'm used to using Mapics Rel6 user exits and can program them no problem, but am totally lost with the Rel7 exits. In fact I don't really understand the 'edit buffer', 'update buffer', etc stuff. I am used to having exits fire at specific times (such as line item detail, end of order,etc). Can someone point me to a research where I can get basic answers to such things as: what the different 'start/finish of protected code' sections are for, how do I send an error message back to the client, what the various variable/data structures are used for,etc.
We had a consultant slightly modify UXPCDO1R, UXPCDQ1R, UXPDEN0R and UXPC6N0R, but his code totally confuses me.

[jdiggs]

I would look at this presentation for starters
does-anyone-have-ali-s-presentation-from-the-last-user-group-t17.html