How to Terminate Cicode Function?

Hi everyone, Using Cicode programming ...
I'm try to make a function empressed Button's input command that still running forever until the user press the Button again .. so if i press the Button at first the function inside Button will be running , But i wonder to terminate that function by press same button second time or don't mind if you suppose other Button for stop running the function ... plz help to make a code or something else to stop running of my function.