public teacher_windows(USER_INF User_Inf_input)
 {
     user_inf       = User_Inf_input;
     mysql_database = new MysqlConnector();
     InitializeComponent();
     show_inf();
 }
        static void Main()
        {
            MysqlConnector mysql_database = new MysqlConnector();

            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            login login_windows = new login();

            login_windows.ShowDialog();
            if (login_windows.DialogResult == DialogResult.OK)
            {
                login_windows.Dispose();
                Application.Run(new admin_windows(login_windows.User_Inf));
            }
            else if (login_windows.DialogResult == DialogResult.Yes)
            {
                login_windows.Dispose();
                Application.Run(new teacher_windows(login_windows.User_Inf));
            }
        }