FirstName, lastName, Birthdate, email

tbEmail and btnLogin

Logins Log = new Logins();

    using (LoginDataEntities lg = new LoginDataEntities())
    {
        string @email = tbUsernameL.Text;
        string @password = tbPassL.Text;

        var logged = from L in lg.Logins
                     where L.Username == @email
                     && L.Pass == @password
                     select L.Username;



        if (logged != null) // update
        {
            lblSuccess.Visible = true;
        }
        else
        {
            lblFail.Visible = true;
        }


    }