login object oriented code

I've reviewed your other questions, you're obviously in the middle of some sort of course, although it's insane, based on the level of experience shown in your other questions, that your class would have you writing ASP.NET code at all, let alone worrying about login controls. The only other option I can think of is that you tried to work through a basic C# book because you'd accepted an ASP.NET job on a rentacoder site. If the former is true, you need to stop asking here, and instead talk to your teacher. This is a great site for programmers to get help, but you're not yet at a level of being able to understand the answers we can give, which means it can't really help you, yet.

If you're taking paid work when you know nothing about programming, then you are a fraud and you should stop it.

i have :

members class that admin class and user class derive of the members class

how i know that when login performed that it is admin or user ?

public class members
{
private string email;
}

public class user:members
{
private string password;
}

public class admin:members
{
private string password;
}

I think that nobody don't understand object oriented programming very good that some of you like Christian Graus says that i don't know programming.

First of all learn 3-tier architecture then you can know how to write the code.