Needle movement script?

Hi,

Im currently trying to create a type of speedometer thing which reacts via various buttons on the screen.

I done a simple script for the needle to move so many degrees left or right but this simple script doesn’t stop the needle from continuing to go to far left or right (min/max on dial). Is there a way of stoping the needle once it has reached say 10 degrees and 120 degrees?

My script is:

bad_btn.onPress = function (){
needle_mc._rotation +=16;
}
good_btn.onPress = function (){
needle_mc._rotation -=16;
}

bad and good buttons determine the left and right

Im also interested in whether once the needle has reached it max point this would trigger of another function etc

Thanks

Spence