I've had a PM from a long-standing forum member and I would like to reply but it seems I don't have enough postings to be able to do so. I can't find how many postings I have to accumulate but never mind - to that member I'd like to say I received your kind message. As regards the technical bit at the end well, I'll have to do a bit of head-scratching there but you know where to get hold of me. Who knows? I may even be able to reply in person by then!