HEllo,
Currently on my website - I have a form which users use to post comments on the website. I want to add an extra check box - that says "Post to my facebook" wall. So if they check that - the comment they post on my website - should also be posted on their website. They should not have to type the comment again.
How do I go about it.
Thanks
Facebook Connect, which is largely a javascript-enabled connection between your site and Facebook, is the answer.
http://developers.facebook.com/connect.php
Not terribly difficult to implement, but you need to be savvy with Javascript. And if you've got your own user membership db (as you likely do), you'll need to wire up the links between your users and facebook id's.
I believe what you are looking for is the comments box, coupled with Facebook Connect it should accomplish what you want.
You'll need to use connect as steve mentioned, specifically the FB.Connect.streamPublish method. I think what you really want to do post your link as a shared stream item, and use the user's comment as the user_message field. The attachment's description would probably be something like "I commented on this article".