App.Web.AccountMembershipService.ValidateUser C# (CSharp) Method

        public bool ValidateUser(string userName, string password)
        {
            if (String.IsNullOrEmpty(userName))
            {
                throw new ArgumentException("Value cannot be null or empty.", "userName");
            }

            if (String.IsNullOrEmpty(password))
            {
                throw new ArgumentException("Value cannot be null or empty.", "password");
            }

            return provider.ValidateUser(userName, password);
        }