EDIT: I've cracked it. Thanks for your help!
Definitely getting there.
Now I have a new problem.
I'm using a wall jump in my game so once the double jump animation has played it will then play for all wall jumps from then on.
I tried using the Else idea but the system wouldn't let me add an else there. Maybe I'm getting the structure wrong?
On the other solution, how do I add an "run once" to something?