这个一个密码锁的程序，在蓝宝石开发板上跑的。预先设置四位密码，如果输入对了就显示正确，如果输入错误连续三次就锁住。-A lock of this program, the development board running sapphire. Four pre-set password, if the input is displayed on the right, if you enter the wrong three times in a row lock.