Forester, thank you so much for the offer, can I take a rain check on it?:) I'm a bit cross at the moment: with incomplete and incorrect documentation, websites that lead me round in ever decreasing circles (anti-cyclones), but most of all with myself for being so unobservant that I can't define a set of behaviours for something I've seen so often as rain and snow. Hey, I live in England, what do we have here but weather? Seriously though, bad tempered isn't the way to conduct a project started for fun and relaxation, so I'm going to forget it for a couple of weeks and try making some static art. John