private void duLieuNSDMenuItem_Click(object sender, EventArgs e) { if (IsOK) { panelControl2.Controls.Clear(); UserPermission managerUser = new UserPermission(userDB, UserNameLogIn); managerUser.Dock = DockStyle.Fill; panelControl2.Controls.Add(managerUser); managerUser.Show(); } else { MessageBox.Show("Bạn chưa có danh mục tham chiếu"); } }