dialog button= attack?

how do u make a unit attack when u press the A button? like sheepball but u attack instead of pass? i admit i tried to look at sheep ball but it was protected. got any ideas?

im gonna make a rifleman shoot whenever u press S or A or F
(im not sure which yet) so im gonna try to make a rapid fire by press ing ssssssssssss, he will shoot about uh.... i think 11 shots, but they will be ********** i dont want any1 to steal.... after or if my map comes out, then ill let u steal :D
plz reply if u have an idea thanks

I never played "sheepball" but it seems to be using weedaar's "WASD" control. I guess the hardest thing to do is to make sure your unit hold the fire till you press the right key.