Yes you are probably correct. I was just thinking that it would be "nice" if it was automatic rather than relying on human intervention. It will probably be the latest list showing anyway I would have thought but it's up to the client of course.
Well unless Jason (or some other kind person) has any further thoughts, I think it will be a case of manually making one list active.
Once again, many, many thanks for your help. I've learnt a lot anyway.