ruby on rails 3 - how can i use fb_server_fbml helper method in facebooker2? -

I am developing a Facebook app using Rail 3 and Facebooker2. How can I use the fb_server_fbml helper method?
What is "proc" in its parameters, can someone provide me the sample code?

Thanks

and more; The Proc parameter is used as a content block which can be found in & lt; Fb: serverFbml & gt; tags, you can learn more about the difference between block helpers and Rail 2.3 and Rail 3:

So, try to do something like this:

  & lt;% fb_server_fbml do% & gt; & Lt; %% Here's your content% & gt; Insert & lt;% end% & gt;   
 If you want to use the request form, try the following:  
  & lt;% fb_server_fbml do% & gt; & Lt;% fb_request_form ("your app name", "http://www.example.com/callback", "try it!") What to do% & gt; & Lt;% = fb_multi_friend_selector ("Invite your friends:", {: lines => 3})%> & Lt;% end% & gt; & Lt;% end% & gt;