private void Button1_Click(object sender, EventArgs e)
    {
        DialogResult dialogResult = MessageBox.Show("Would you like to play again?", "No would result in the application closing"), MessageBoxButtons.YesNo;
        if (dialogResult == DialogResult.Yes)
        {
            Application.Exit();
        }
        else if (dialogResult == DialogResult.No)
        {
            MainWindow window1 = new MainWindow();
            window1.Show();
            this.Close();
        }
    }