I have to print comments.in textbox..I am unable to do it. kindly see GUI attachments and code.

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

namespace WindowsFormsApplication4
{
    public partial class MyForm : Form
    {
        public MyForm()
        {
            InitializeComponent();
        }

        private void btnexit_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }

        private void checkBox1_CheckedChanged(object sender, EventArgs e)
        {
            if (checkBox1.Checked == false && checkBox2.Checked == false && checkBox3.Checked == false)
            {
                gbxpaymnetmode.Enabled = false;
                purchasebutton.Enabled = false;

            }

            else
            {
                gbxpaymnetmode.Enabled = true;
                purchasebutton.Enabled = true;
            }
        }

        private void checkBox2_CheckedChanged(object sender, EventArgs e)
        {
            if (checkBox1.Checked == false && checkBox2.Checked == false && checkBox3.Checked == false)
            {
                gbxpaymnetmode.Enabled = false;
                purchasebutton.Enabled = false;

            }

            else
            {
                gbxpaymnetmode.Enabled = true;
                purchasebutton.Enabled = true;
            }
        }

        private void checkBox3_CheckedChanged(object sender, EventArgs e)
        {
            if (checkBox1.Checked == false && checkBox2.Checked == false && checkBox3.Checked == false)
            {
                gbxpaymnetmode.Enabled = false;
                purchasebutton.Enabled = false;

            }

            else
            {
                gbxpaymnetmode.Enabled = true;
                purchasebutton.Enabled = true;
            }
        }

        private void purchasebutton_Click(object sender, EventArgs e)
        {
            string message = "order purchased";
            int amount = 0;

            if (checkBox1.Checked)
            {
                amount += 20;
                message += checkBox1.Text;

            }
            if (checkBox2.Checked)
            {
                amount += 30;
                message += checkBox2.Text;

            }
            if (checkBox3.Checked)
            {
                amount += 50;
                message += checkBox3.Text;

            }
            string paymentmode = " ";
            if (fullpaymnet.Checked)
            {
                paymentmode=fullpaymnet.Text;

            }
            else
            {
                paymentmode = installement.Text;

            }
            message += "\r\n amount due is $" + amount.ToString();
            message += "\r\n paymnet mode is" + paymentmode;

            if (label4.Text != "")
            {
                message += "\r\n your comments" + label4.Text;
            }
            MessageBox.Show(message, "\r\n experience is nice");
        }

        private void label4_Click(object sender, EventArgs e)
        {

        }
    }
}

    

thanks and regard love4csharp