public String invokeAction(String keyword, String argument)
    {
        String answer = "";

        switch(keyword) {
            case "go":
                answer = go(argument);
                break;
            case "back":
                answer = back(argument);
                break;
            case "manual":
                answer = commandWords.manual(argument);
                break;
            case "use":
                answer = use(argument);
                break;
            case "pickup":
                answer = pickup(argument);
                break;
            case "drop":
                answer = drop(argument);
                break;
            case "inspect":
                answer = inspect(argument);
                break;
            case "new":
                answer = newGame(argument);
                break;
        }

        return answer;
    }