SVG with animtion script

<svg
  width="100%"
  height="100%"
  viewBox="0 0 100 100"
  xmlns="http://www.w3.org/2000/svg">
  <script type="text/javascript">
    // <![CDATA[
    function change(evt) {
      var target = evt.target;
      var radius = target.getAttribute("r");

      if (radius == 15) {
        radius = 45;
      } else {
        radius = 15;
      }

      target.setAttribute("r", radius);
    }
    // ]]>
  </script>

  <circle cx="50" cy="50" r="45" fill="green" onclick="change(evt)" />
</svg>