Hi
I'm just back on this again and am astounded by the brilliant replies.
Particular thanks for the superb code - I have learned a lot of new things from this. Metra and Rich - great thanks for your extensive efforts. There are some very possible solutions in this.
Rich, the link to Stephen Leban's site is particularly welcome. It has the solution to my problem with the memo field, and many other things I have often wondered about.
A great many thanks to everybody
Paul