title: Adding Cancel Button to Javascript Alert
body: <p>Here is my Javascript Alert:</p>
  <pre><code>&lt;script&gt;
  function showMessage() {
      setTimeout(function() {
  alert(&quot;alert&quot;);
  }, 100);
  }
  &lt;/script&gt;
  </code></pre>
  <p>When a user visits a page, a window pops up that says &quot;alert&quot; and it only has the &quot;Ok&quot; button. When it is clicked, the window goes away and displays the page under it. How do I add a &quot;Cancel&quot; button that has the same effect?</p>