Well, it really depends how you're doing it. If your player is a movieclip and your attack animations are all on one timeline, you can do something like have a variable called attackFrame and set it to the first frame of "Attack 1". Then, have some actionscript in the "Attack 1" sequence set it to the first frame of "Attack 2", and so on. Then when the spacebar is pressed, just use gotoAndPlay(attackFrame).