onClipEvent (load) {
     power = 0.3;
     yspeed = 0;
     xspeed = 0;
     friction = 0.95;
     gravity = 0.1;
     thrust = 0.75;
     wind = 0.09;
 }
onClipEvent (enterFrame) {
    if (Key.isDown(Key.LEFT)) {
        xspeed -= power;
    }
    if (Key.isDown(Key.RIGHT)) {
        xspeed += power;
    }
    if (Key.isDown(Key.UP)) {
        yspeed -= power*thrust;
    }
    if (Key.isDown(Key.DOWN)) {
        yspeed += power*thrust;
    }
    xspeed += wind;
    xspeed *= friction;
    yspeed += gravity;
    _y += yspeed;
    _x += xspeed;
}