protected Animation dropBalls (ImageLayer[] balls, int offset, int count) {
float startY = 350;
AnimGroup group = new AnimGroup();
for (int ii = 0; ii < count; ii++) {
ImageLayer ball = balls[ii+offset];
group.tweenY(ball).to(startY+100).in(1000).easeIn().then().
tweenY(ball).to(startY).in(1000).easeOut();
}
return group.toAnim();
}