Invite Friends : Facebook App with Rails

<fb:fbml>
<fb:add-section-button section="profile" />
<% fb_multi_friend_request("Ripple Effect",
"Invite your friends to use Ripple Effect",
invitations_path) do %>
     Ripple Effect your friends. Install Ripple Effect now.
     <%= fb_req_choice("Ripple Effect!",
     new_invitation_url(:from=>@from_user_id, :canvas=>true))%>
     <% end %>
</fb:fbml>