Cheers for all the pointers guys, really helpful! Since posting I've been carrying on with the book and learned about strict and my and after you all pointing them out they'll be in common use now! Plus, I can see how I've repeated alot of the calculations when they're not needed. Haven't got as far as grep yet but I can see the gist from this, and modules are pretty far in my future I think.

To summarise, B- for first code, A+ for personal development!

Thanks, M