That's probably a Mac or Windows thing, because those keys have multiple functionalities depending on how you're using them. You may have to go into your operating system and change the keyboard functionality. It will be different depending if you're on Mac, Windows or Linux. A quick google search will probably solve it.
I'm going to guess you're using Mac.(if I remember correctly this is a common problem with the MacBook) Under system settings there's an option to change the function keys to standard. The other option if I remember correctly is there's a FN key you press when you press the F keys to get the standard function key. Sorry, it's been a long time since I've seen this problem.
