woah mike, that was a pretty solid code effort just to help out, very nice.
Just a suggestion then for you Gurkay.
you could declare another variable at the start of your code say:
boolean stopped = false;
then, instead of hold delay (which is just meant to DELAY it) you could tweak the code so that after a button press it just executes something like:
stopped = !stopped;
that should toggle the stopped vairable for you.
then all you have to do is guard your code that increments "num" with the if statement:
if(!stopped)
num++
Theres better ways, but conceptually, that should be easy for you to get your head around 
By the way, ! means not.
Good luck.