ASP.NET用户注册及判断用户是否在在的小例子，连接了Access数据库，页面没有过多美化，相对粗糙一些，功能上还有大大提长的空间，本例更适合初学者阅读学习。-ASP.NET user registration and to determine whether the user is in a small example, is connected to an Access database, page not too much landscaping, relatively rough fu