functions dont work and help

hello, i have some problem with getting functions to work and im trying to make a detect program but it worn't work.
first off: functions

if i just type turtle.forward() in a program it works fine but if i type function move() turtle.forward() end. it dont work anymore and i cant figure out why i have seen alot of videos and search on the forum to see if i do anyting wrong but i dont think i do

detect programs:
im trying to make a detect programs for my tree farm but i cant figure out how to loop it i want it to go up, detect, if true dig() if false down()
i think i have trying everything but it worn't work prob cuz my functions dont work but still

hope some1 can help me a little. thank you for your time

-high v01tage

So, you're doing:

function move()
  turtle.forward()
end

move()

And nothing happens? You need to provide us with the actual code you're using either way, but my guess is that you weren't calling the function. For the other question, please provide your current code.