Thanks Barb, Steve, ChattanCat and Moosedog... its starting to become clear - ... (like Barbs book says: beginners dont get "you'll just know when its right" - they prefer an exact equation! )

Right - onwards and upwards - time to get back to it! I'll post some pics as I progress - bit of a blog - not done one of those yet.

Thanks again.... XMarksTheScot Rocks! (ahem - as they say....)