Checkbox Errors

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;
using System.Web;

namespace Page_75_Exercise
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            if (checkBox1.Checked == true)
            {

                if (label1.BackColor == Color.Red)
                {

                    label1.BackColor = Color.Blue;
                }

                else
                {
                    label1.BackColor = Color.Red;
                }

            }
            else
            {
                MessageBox.Show("The Checkbox is not selected!");
            }
        }
    }
}