sometimes we need to do something to each item in a list or array. to do that we use a
				java script feature called 'loops'

				loops are a way to repeat the same code a number of times. specifically, this is a for loop.

				one thing you need to be careful of with loops is that you set them up correctly so that they can terminate,
				if you don't, it can cause the browser window to lock up. even if that happens though, don't worry, just quit
				the browser and fix the loop.