Mathematical curves.
See Swishmax to learn more about this example. Not so easy.
A button click allows you to go from scene to scene; but as there are cloned sprites, you need to destroy them when you click on Return button.
Therefore, this button 'll have a script :
on (press)
{
for (i=1; i < n; i++) eval("dot"+i).unloadMovie();
gotoSceneAndPlay("Scene_0",1);
}
n is the number of clones ( global variable in onLoad )
dot is the genuine sprite.
Scene_0 permits to go to whatever scene.