说明：  本系统主要实现ATM提款机的主要功能，包括系统自动识别卡号，验证用户信息（如果输入的密码三次错误时，系统自动扣留本信用卡），查询当前用户信用卡的余额，修改用户密码，打印清单，取款等功能。
(The system is mainly to achieve the main function of ATM cash machines, including automatic identification card system to verify user information (if you enter wrong password three times, the system automatically detain the credit card), check the current balance of credit card users, change user passwords, print list of withdrawals and other functions.)