How to detect that there is no activity from user in last 20 seconds(php)
<blockquote>
  <p><strong>Possible Duplicate:</strong><br>
  <a href="http://stackoverflow.com/questions/667555/detecting-idle-time-in-javascript-elegantly">Detecting idle time in JavaScript elegantly</a>  </p>
</blockquote>



<p>I am working on a website and I want the cursor to be placed in a particular textbox if there is no activity from the user since last 20 seconds. Please help.</p>
