How do you take a screenshot on Pirates of the Caribbean online

well this is my answer, on a PC you have to hit f9 and it takes a screenshot! but if you have a mac then you use the button in the bottom left corner called the FN on the macbook! use the f9 and FN together so it would show up right... after that it says on it where it is and it will show up!
NOTE: it only works if its fullscreen!!!