Thanks Dave, thats solved the first choice part, is there anyway of making it so I can return it to the beginning of the program if x isn't 1/2/3? Also what can I do about the entering of measurements in the rest of the program? for instance, if someone puts in an alphabet character instead of a number? I've tried using <65536 sort of checks, but then a characteer seems to be recognised as a value...is there any form of checking the type of input? By the way, I'm using version 4, but im gonna start the new update in a while *kicks 56k modem*.

Thanks alo for your help!

Jake

Jakeyboy - Annoying Maths Teachers from the comfort of his caravan