Invite friends from facebook on my application using facebook api

I create a application which allow user integration through facebook(开发者_运维技巧connect with facebook).when user sign-in in application , i want to show all facebook friends of sign-in user for invite them to join my application.

In current i am using multi friend selector for invite friends.

<fb:serverfbml width="615">
<script type="text/fbml">
<fb:request-form action="action url"
method="POST"
invite="true"
type="invite"
content=" my message">
<fb:multi-friend-selector showborder="true"
bypass="cancel"
cols=3
email_invite="false"
import_external_friends="false"
actiontext="Invite your friend from facebook"/>
</fb:request-form>
</script>
</fb:serverfbml>

I want to customize mult friend selector 1 Can change css and show all friend in a single column? 2 can i show disable the friends whose are already connect with my application?

please give your suggestion or if any other option for this.

Thanks

Just change the cols parameter for the number of columns, and use the exclude_ids array to, well, exclude the ids you want. It's all here: http://developers.facebook.com/docs/reference/fbml/multi-friend-selector

I think it is the URL to which facebook redirect when the friend accept the invitation