keyDown to frame question

programming flash
1

I have code that, when pressing the left or right key, will go to the next frame within my movie:

stop();

this.onKeyDown = function() {
    if (Key.getCode() == Key.LEFT) {
        this.prevFrame();
    } else if (Key.getCode() == Key.RIGHT) {
        this.nextFrame();
    } 
};
Key.addListener(this);

However, this will go to the next frame and stop.

How can I get it so it will go to the next frame and play through the time line until I put in a stop command?
Or, along the same lines, how could I set it so on keyDown it will go to and play whatever frame I choose?