Delay Apologies for the delay, this week I've just started back at university so I've been busy. I've got a new tutorial, still with excel, lined up that I hope to post by this weekend. As for future tutorials, which way would you like me to go: I can keep with excel and cover more maths, looking at physics and graphics, or I can make a move into programming C++/OpenGL. Also I've changed the comment options here, now anyone can comment. Cheers thing2k