title: automatically refresh ads on website
body: <p>I am using sovrn ad network at my website, here are a few script lines:</p>
  
  <pre><code>&lt;script type="text/javascript" src="http://ap.lijit.com/www/delivery/fpi.js?z=1&amp;u=abc&amp;width=300&amp;height=600"&gt;&lt;/script&gt;
  &lt;script type="text/javascript" src="http://ap.lijit.com/www/delivery/fpi.js?z=2&amp;u=abc&amp;width=300&amp;height=250"&gt;&lt;/script&gt;
  </code></pre>
  
  <p>I would like to refresh every ad position each 20 seconds. Any idea how to refresh just ad positions withou refreshing whole page?</p>