negotiate({make_bid, Item, Price}, S=#state{}) ->
  if
    (S#state.tradeditem == Item) ->
      do_bid(S#state.other, Item, Price),
      notice(S, "bidding $~p on ~p", [Price, Item]),
      {next_state, negotiate, S#state{ourprice=Price}};
    true ->
      io:format("~p: Cannot bid. Item ~p is not connected with any offer.~n", [S#state.name, Item]),
      {next_state, negotiate, S#state{}}
  end;