animation.js

var paper = Raphael("animation", 785, 200);
var left, right, circle = paper.circle(30, 100, 20).attr("fill", "black");
right = function() {
  circle.animate({cx: 700, r: 80, fill: "red"}, 3000, "bounce");
  circle.node.onclick = left;
};
left = function() {
  circle.animate({cx: 30, r: 10, fill: "black"}, 3000, "bounce");
  circle.node.onclick = right;
}
circle.node.onclick = right;