codice:
<script>
function toggle()
{
  var animation=document.getElementById("animation");
  if(animation.className=="transition0"){
 animation.className="transition1"}
  else if(animation.className=="transition1"){
animation.className="transition2"}
else if(animation.className=="transition2"){
animation.className="transition3"}
else if(animation.className=="transition3"){
  animation.className="transition4"}
else if(animation.className="transition4"){
 animation.className="transition0"}
}
</script>