private void button2_Click(object sender, EventArgs e)
        {
            ManageFood manage = new ManageFood();

            this.Hide();
            manage.Show();
        }
        private void loginButton_Click(object sender, EventArgs e)
        {
            LoginService loginService = new LoginService();
            int          result       = loginService.LoginValidation(usernameTextBox.Text, passwordTextBox.Text);

            if (result == 1)
            {
                Dashboard dashboard = new Dashboard();
                this.Hide();
                dashboard.Show();
            }
            else if (result == 2)
            {
                ManageFood manageProduct = new ManageFood();
                this.Hide();
                manageProduct.Show();
            }
            else if (result > 2)
            {
                ManageFood manageProduct = new ManageFood();
                this.Hide();
                manageProduct.Show();
            }
            else
            {
                MessageBox.Show("Invalid username or password");
            }
        }