Windows authentication

Question

HI All,
we have a ASp .net  application( C#). I need to authenticate user using Windows Authentication mode. i.e When a user tries to access the developed Web form , the windows authentication logon screen should pop up asking for the user credentials ( user name , user password, domain). Our requirement is to use the default windows logon screen which generally pops up to get the user credential instead of the custom developed logon screen.
any idea about it?