title: How to define DO NOTHING in JavaScript
body: <p>I am displaying a confirm box in my app. When the user clicks on <code>Okay</code>, I close the window<br>
  when user clicks on <code>Cancel</code>, I want to do nothing but stay on the same page.  </p>
  
  <p>What should I write in place of DO_NOTHING?</p>
  
  <pre><code>    &lt;a href="#" onclick="confirm('Do you wan to close the application ?')?window.close():DO_NOTHING')"&gt;Close the application ?&lt;/a&gt; 
  </code></pre>
  
  <p>If I keep it empty it does not work. If I write any random string it works but displays <code>string undefined</code> error.</p>