Ok now this is all starting to make sense. I think this is why I was confused. There are two ways to setup my Function. The first would be to Globally declare my Function and thereby locking a specific LED to have the "flashing" action. The downside is I can't re-use the code that controls the "flashing" on say another LED. The second method involves creating a function for the act of flashing an LED but not specifying which particular LED. But this method requires you to setup the Function to accept Arguments. In this case the Argument would be a variable to hold which particular LED I would like to flash - is this correct? If so, how would I setup my function to accept a single argument, say my output pin for example? I would be very grateful for a clear example of this.