title: Add a fadeIn to a switch from hide to block display
body: <p>I have a </p>
  
  <pre><code>&lt;a onclick="document.getElementById('massage').style.display = 'block';"&gt;Button&lt;/a&gt;
  </code></pre>
  
  <p>And I want to add a fadeIn to the function, but dont know how.</p>