Help with jumping physics!

Hey, currently, my game feels a bit broken because i only want the character to be able to double jump before hitting the floor, but currently you can jump infinitely, how do i fix this?

Gimme a sec

Here you go
Screenshot 2018-02-25 at 4.11.43 PM

Thanks @SnakeInMyHoot ! I just implemented it, it feels a lot more fair!