I am using the following script to share links with Facebook:
<script>function fbs_click() {u=location.href;t=document.title;window.open('http://www.facebook.com/sharer.php?u='+encodeURIComponent(u)+'&t='+encodeURIComponent(t),'sharer','toolbar=0,status=0,width=626,height=436');return false;}</script><a href="http://www.facebook.com/share.php?u=<url>" onclick="return fbs_click()" target="_blank">Share on Facebook</a>
When facebook share screen popup opens it displayes title and description. I want to provide my own title and description of share are there parameters available for this?
Create a Facebook Application at http://developers.facebook.com/
Then embed Open Graph metatags in your document that describe to the Facebook document linter which title, image, description, and URL to use when shared.
Open Graph Documentation
Open Graph Debugger
Here is an example copied from the Facebook documentation that shows the Open Graph meta tags used to describe a website.