<html>
  <head>
    <title>Test page</title>
  </head>
  <body>
  <div style="text-align: center;margin:10em;">
    <h3 id="the_string"> Nothing to echo </h3>
  </div>
  <script>
    var h = document.getElementById('the_string');
    h.innerText = decodeURIComponent(document.location.search.substring(1));
  </script>
  </body>
</html>