Analysis in SM35

Hi guys,

Whenever i do a BDC session program, i found a few things that i really do not know why it happen, even though my program works. There are a few items found in sm35 that i do not understand.

In the analysis->log part after i done process my session, i found that there will be a list of "Screen not required". Why do i have these screens? Is it that the session does not required some the screens i am using?

I tried taking away a few screen. If i do that, my bdc won't work.

Is there any website or technical help page that will help me to understand more and detail about SM35 and BDC? I don't meant the tutorial but something like bible of sm35 or whitepapter or something like 'everything you need to know on bdc or sm35'.

Thank you so much

william wilstroth.