Вот правильно

[birdwatcher]

If you are in an airline club, and you have been given a free drink coupon, what you are supposed to do is take the coupon to the counter, get your drink, and use the price you would have paid to tip the server.
Because if you are in an airline club, you can afford that drink, and the server could use some help.

Хорстман, по рекомендации piggymouse.