How do I make the player stop moving X on jump

Hi

I'm making a smash attack on jump when pressing down, like some platformers do. I have everything set up nicely but one thing:

I want the player X to stop whenever you press the down key, which means, when you decide to do the attack the player should stop moving at the point you press the attack.

I believe super mario does this thing nowadays in the wii games.

Add the invert of keyboard > Key is down (down) to the other key capturing events ?

Add the invert of keyboard > Key is down (down) to the other key capturing events ?

Could you explain a bit further? I'm really noobish, just learning slowly

https://www.dropbox.com/s/v7o2q0dndlchx ... .capx?dl=0