I have implemented the facebook share feature in JavaScript. So far, when i click, a popup show up with the title of the document, the url and an image. I need to add a small description like this one:

So far, my code is this:
window.open('http://www.facebook.com/sharer.php?u='+encodeURIComponent('http://xxxxx.com/myblog')+'&t='+encodeURIComponent(''),'sharer','toolbar=0,status=0,width=626,height=436');
Is there any thing to add to make the description appear on the sharer popup window?
On the page you want to share (http://xxxxx.com/myblog) you need to add the FB Open Graph Tags
This tag add the description
Read more @ http://developers.facebook.com/docs/opengraphprotocol/