anchor.diff:        FbName
     end.
   
  +auth_link() ->
  +  "http://www.facebook.com/connect/uiserver.php?"
  +    "app_id=" ++ app_id() ++ "&"
  +    "method=permissions.request" ++ "&"
  +    "redirect_uri=" ++ login_redirect_uri() ++ "&"
  +    "response_type=code" ++ "&"
  +    "display=async" ++ "&"
  +    "perms=" ++ data_perms() ++ "&"
  +    "auth_referral=1".
  +
   app_id() ->
     mtc:get_env(facebook_app_id, "dummy_app_id").
   
  
positive.code:       SignedRequest = wf:q(signed_request),
        ?DBG("LogOff: signed_request=~p", [SignedRequest]),
        wf:redirect(mtc:get_env(url));
       true ->
        Code = wf:q(code),
        Req =
  
negative.code:   FbLink = wf:session(facebook_link),
    if
      FbLink =:= undefined ->
          mtc:get_env(url) ++ "/facebook?action=login";
      true ->
        FbLink
    end.
  