How to use Facebook FBJS Feed Forms

I'm trying to call a Feed Form in my Facebook application and I'm not sure how to do so. I'm not familiar with the FBJS and its API. Specifically I need the following dialogue to show up: http://wiki.developers.facebook.com/index.php/Feed_Forms

Here's what I got for now:

<script type="text/javascript">var attachment = <?php echo json_encode($attachment); ?>;return attachment;Facebook.streamPublish(<?php echo $message; ?>, attachment, null, <?php echo $user; ?>);</script>

Is there anything else I need to do in order to properly call a Feed form? A code example would help me a lot if anyone is willing to write one up.