<html>
  <head>
    <meta charset="utf-8" />
  </head>
  <header><title>Title1</title></header>
  <body>
    <script>
      addEventListener("load", function () {
        setTimeout(function () {
          document.title = "Title2";
        }, 100);
      });
    </script>
  </body>
  <iframe src="hello.html"></iframe>
</html>
