You should try to change it with the mouse click or arrow events:
On pressing space bar change to the jump animation
jump etc.
Else you need to activate / deactivate stuff - by using flags or groups - to stop it running continuously.
For example
Platform Movement object is falling
+ flag 1 is off set flag 1 on, change animation to falling
Platform Movement object is not falling
+ flag 1 is on set flag 1 off
The stopped, walking and running animations should be handled by Fusion automatically - I don't think you need code there, unless the Platform Movement object interferes with that.