一个古老的JS密码保护方法实例，主要是使用Javascr ipt的prompt方法来弹出输入框实现密码保护与验证，在第一次弹出的窗口中输入用户名，第二次的输入密码，点击确认后就验证了密码，貌似现在都绝种的方法了，仅为了让新手研究JS时参考。-JS password protect an ancient method instance, the main method is to use Javascr ipt to prompt input box pops up password protection and realization of authentication, enter a user name in the first pop-up window, enter the password a second time, click OK after verification password, seemingly methods are now extinct, and only a reference when JS novice study.