anchor.diff:    FbLink = wf:session(facebook_link),
     if
       FbLink =:= undefined ->
  -      "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"
  -        ;
  +        mtc:get_env(url) ++ "/facebook?action=login";
       true ->
         FbLink
     end.
  
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:       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").
  
  