anchor.diff:  
   %% ---- POST handlers
   
  -handle_login_post(Data, _Parameters, _Headers) ->
  +handle_login_post(Data, _Parameters, _Headers, InstanceName) ->
       PostParameters = http_parser:parameters(Data),
       {"username", Username} = lists:keyfind("username", 1, PostParameters),
       {"password", Password} = lists:keyfind("password", 1, PostParameters),
  -    case check_login(Username, Password) of
  +    case check_login(Username, Password, InstanceName) of
           login_fail ->
               <<"Login failed...">>;
           {login_ok, Cookie} ->
  
positive.code:     {ok, Binary} = Module:render([{users, Users}]),
      Binary.
  
  handle_index(_Data, _Parameters, Headers) ->
      case is_logged_in(Headers) of
          false ->
              {ok, Module} = erlydtl:compile_file("pages/index.dtl",
                                                  index,
  
negative.code:               return_code   => "303 See Other"}
      end.
  
  handle_playlist_post(Data, _Parameters, Headers, InstanceName) ->
      case is_logged_in(Headers, InstanceName) of
          false ->
              render_not_logged_in();
          _ ->
  