Arduino Multitasking

Im working on project with timer from 0-999 and thermometer 0-600C and i want that to work on same arduino but without interferencing eachother, when i use delay for thermometer for lcd it messes up with my timer. Then i left this project for a year i didnt touched it and i lost old code, i have no idea what to do or how to start code, guys can somebody tell me head structure of code 2 voids that run at same time.

voids? Do you mean functions? void is a type meaning no value.

Go to the blinkWithoutDelay example in the first instance to see how to avoid calling delay()

The demo Several Things at a Time is an extended example of BWoD.

...R

Or see my http://www.thebox.myzen.co.uk/Tutorial/State_Machine.html