net Web Forms应用程序登录使用外部数据库。

I'am creating a dynamic web form aplication. It stores the users data in another database (external server) I know that there is aspnet_regsql.exe but i have no idea how to implement it on external server. (i also can't loose data from existing database) How can i force default login system to check if my database have valid credentials in my Password and UserName columns ? I'am creating a dynamic web form aplication. It