Before anyone says "He would say that wouldn't he" - I did think of this the other day and it came back to me after I opened the thread.
I've often found that sometimes typing a question is a trigger to a little grey cell and the answer appears, as if by magic.
Before opening the replies I told my wife what the response would be - go on ask her!
Anyway - thanks again for your swift replies.
This forum has often saved what sanity I have!