拟饮料自动售卖机的销售过程。顾客首先进行投币，机器显示投币金额。接下

来顾客选择要购买的饮料，如果投币金额足够并且所购饮料存在，则提示用户在出口处取走饮料，同时找零。如果投币金额不足，显示提示信息。如果所购饮料已经售完，显示售完信息-Intends beverage vending machines selling process. Customer first for the coin, the machine displays the amount of coin. Next customers choose to purchase drinks, and if sufficient amount of coin purchased drinks exist, the user is prompted to take away drinks at the exit, but give change. If the amount of coin shortage prompts. If the purchase of drinks have been sold out show sold out information