If I should ever happen to be introducing you to someone in the future, I shall try to remember to do it as "...and this is ludicrously clever Simon". You're not allowed to blush :)

It is indeed very satisfying to code a solution that you can be that proud of. Lots and lots of 'go you'.

Good luck explaining reality to British Gas. I had fun with them when I moved out of my house in MK - they started billing the new tenant (my sister), kept billing me too, then tried to take me to court despite the fact that she'd paid all the bills.

I don't believe this is anything specific to BG. So far as I can tell, all billing systems are broken.