Thanks bookworm (and Irv) - helps a lot to see what it really looks like. Still plenty of things I'm confused about, but they are a bit OTT for the PPL. I'll get the exam out of the way at the weekend, but I'm not done with Met yet. I've become rather interested in it now... <img src="redface.gif" border="0"> <img src="smile.gif" border="0">