HTML Code

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>Update cookie value</title>
</head>
<body>
  <h1>Update cookie value</h1>
  <button type="button" id="run">Update username</button>
  <pre id="out"></pre>
  <script>
    document.getElementById("run").addEventListener("click", function () {
      document.cookie = "username=JohnDoe; max-age=604800; path=/";
      document.cookie = "username=JaneDoe; max-age=604800; path=/";
      document.getElementById("out").textContent = document.cookie;
    });
  </script>
</body>
</html>

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