When I had to learn how to use timers, I used this thread.

This thread also happens to have EXACTLY what you want... a timer that counts down from 30.

http://www.picbasic.co.uk/forum/show...hlight=O_FLOWS

Sorry the link highlights O_FLOWS, I just happen to rememberthat variable so used it to find the thread.
Also wish I'd have read the forum sooner >.<;