C++ Quiz Form2

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

namespace WindowsFormsApplication3
{
    public partial class Form2 : Form
    {
        int m, s;
        public Form2()
        {
            InitializeComponent();
        }
        private void button1_Click(object sender, EventArgs e)
        {
         //   MessageBox.Show("Answer is not correct");
            this.Visible = true;
            Form2 form2 = new Form2();
            DialogResult dialog =MessageBox.Show("Answer is not correct! Do you want to play again?", "Quiz", MessageBoxButtons.YesNo, MessageBoxIcon.Information);
            if(dialog == DialogResult.Yes)
            {
                this.Visible = false;
                form2.Show();
            }
            else if(dialog == DialogResult.No)
            {
                //e.Cancel = true;
                Application.Exit();
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            //    MessageBox.Show("Answer is correct");
            button2.BackColor = Color.Green;
            this.Visible = false;
            Form3 form3 = new Form3();
            form3.Show();
        }

        private void button3_Click(object sender, EventArgs e)
        {
            this.Visible = true;
            Form2 form2 = new Form2();
            DialogResult dialog = MessageBox.Show("Answer is not correct! Do you want to play again?", "Quiz", MessageBoxButtons.YesNo, MessageBoxIcon.Information);
            if (dialog == DialogResult.Yes)
            {
                this.Visible = false;
                form2.Show();
            }
            else if (dialog == DialogResult.No)
            {
                //e.Cancel = true;
                Application.Exit();
            }
        }

        private void button4_Click(object sender, EventArgs e)
        {
            this.Visible = true;
            Form2 form2 = new Form2();
            DialogResult dialog = MessageBox.Show("Answer is not correct! Do you want to play again?", "Quiz", MessageBoxButtons.YesNo, MessageBoxIcon.Information);
            if (dialog == DialogResult.Yes)
            {
                this.Visible = false;
                form2.Show();
            }
            else if (dialog == DialogResult.No)
            {
                //e.Cancel = true;
                Application.Exit();
            }
        }

        private void button5_Click(object sender, EventArgs e)
        {
            MessageBox.Show("Answer is private");
            this.Visible = false;
            Form3 form3 = new Form3();
            form3.Show();
        }

        private void button6_Click(object sender, EventArgs e)
        {
            button3.Enabled = false;
            button4.Enabled = false;
        }
    }
}