C#'da yapılan clicker çalışmıyor

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Runtime.InteropServices;

using System.Text;

using System.Threading.Tasks;

using System.Windows.Forms;

using System.Threading;



namespace aaaa

{

    public partial class Form1 : Form

    {

        [DllImport("user32.dll")]

        static extern short GetAsyncKeyState(Keys vKey);



        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]

        public static extern void mouse_event(int dwFlags, int dx, int dy, int cButtons, int dwExtraInfo);



        private const int LEFTUP = 0x0004;

        private const int LEFTDOWN = 0x0002;

        public int intervals = 5;

        public bool Click = false;

        public int parsedValue;

        public Form1()

        {

            InitializeComponent();

        }



        private void Form1_Load(object sender, EventArgs e)

        {

            CheckForIllegalCrossThreadCalls = false;

            Thread AC = new Thread(AutoClick);

            backgroundWorker1.RunWorkerAsync();

            AC.Start();

        }

        private void AutoClick()

        {

            while (true)

            {

                if (Click == true)

                {

                    mouse_event(dwFlags: LEFTUP, dx: 0, dy: 0, cButtons: 0, dwExtraInfo: 0);

                    Thread.Sleep(1);

                    mouse_event(dwFlags: LEFTDOWN, dx: 0, dy: 0, cButtons: 0, dwExtraInfo: 0);

                    Thread.Sleep(intervals);

                }

                Thread.Sleep(2);

            }

        }



        private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)

        {

            while (true)

            {

                if (checkBox1.Checked)

                {

                    if (GetAsyncKeyState(Keys.Down)< 0)

                    {

                        Click = false;

                    }

                    else if(GetAsyncKeyState(Keys.Up)< 0)

                    {

                        Click = true;

                    }

                    Thread.Sleep(1);

                }

                Thread.Sleep(1);

            }

          

        }



        private void button1_Click(object sender, EventArgs e)

        {

            if (!int.TryParse(textBox1.Text, out parsedValue))

            {

                MessageBox.Show("Please enter a number ");

                return;

            }

            else

            {

                intervals = int.Parse(textBox1.Text);

            }

        }

    }

}