Well, those responses were both quick and illuminating! Unfortunately, a couple of hours of experimenting and my loops won't work (the compiler tells me I need an "else" and then tells me that the else isn't associated with a for..next!).

I've spent too long on trying to learn today - time to try again tomorrow. Thanks for everybody's assistance though; I'll press on with it during the week and see if anything begins to sink in.

Cheers

RMC, England