Arkanoid game Help!

Im makin an arkanoid game for a school assignment, and run into a problem. The actionscript for the ball which ive written below seems to be wrong, but i dont know wat.
Instead of the ball bouncing off the paddle, the ball kinda rolls off to the side of it after making contact. Please HELP!!

onClipEvent (load) { movespeed = 10; }
onClipEvent (enterFrame)
{
_x += movespeed;
_y += movespeed;
{if (_parent.paddle.hitTest (this))
{
_x += movespeed;
_y += -movespeed;
}
}
}