Form 4 - Авторизация

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Data.Linq;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace laba8
{
    public partial class Form4 : Form
    {
        Table<User> users;
        Table<Priv> privs;
        Table<UserPriv> userPrivs;
        DataContext context;

        public Form4()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            context = appcontext.GetDataContext();
            users = context.GetTable<User>();
            privs = context.GetTable<Priv>();
            userPrivs = context.GetTable<UserPriv>();
            var user = users.FirstOrDefault(v => v.UserName == textBox1.Text && v.Password == textBox2.Text);
            if (user != null)
            {
                Program.user = user;
                new Form1().Show();
                this.Hide();
            }
            else
            {
                MessageBox.Show("Неверный логин или пароль");
            }

        }
    }
}