C ＃ simulation lottery

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;

using System.Threading;

namespace  Multi thread simulation lottery 
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        bool b=false;
        private void button1_Click(object sender, EventArgs e)
        {

            if (b == false)
            {
                b = true;
                Thread thread = new Thread(playGame);
                thread.IsBackground = true;
                thread.Start();
                button1.Text = " stop it ";
            }
            else
            {
                button1.Text = " Start ";
                b = false;
            }            
        }
        private void playGame()
        {
            Random random = new Random();
            while (b)
            {
                Thread.Sleep(100);
                label1.Text = random.Next(1,10).ToString();
                label2.Text = random.Next(1, 10).ToString();
                label3.Text = random.Next(1, 10).ToString();
            }
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            Control.CheckForIllegalCrossThreadCalls=false;
        }
    }
}