I dont know how the hell to make a character move with a series of animations.

I want it to run 3 or 4 pictures in a row when i push a key, seperated by about a half a second. I also want it to rerun the series for as long as the key is pushed. I know how to loop it but I want it to stop when I release the key.

I know this is dumb but, hey, Im new at this stuff