private void button5_Click(object sender, EventArgs e)
        {
            driver.Navigate().GoToUrl("https://web.whatsapp.com/");
            richTextBox1.Text += "Logging in.\n";
            timer6.Start(); //timer7.Start();
        }
        private void timer6_Tick(object sender, EventArgs e)
        {
            if (IsElementPresent(By.ClassName("iHhHL")))
            {
                driver.Navigate().GoToUrl("https://api.whatsapp.com/send?phone=" + listBox2.Text);
                C++;
                listBox2.SelectedItem = listBox2.Items[C - 1];
                timer6.Stop();
                timer7.Start();
            }
        }

        private void timer7_Tick(object sender, EventArgs e)
        {
            if (IsElementaction(By.Id("action-button")))
            {
                driver.FindElement(By.Id("action-button")).Click();
            }

            timer7.Stop();
            timer8.Start();
        }
        private void timer8_Tick(object sender, EventArgs e)
        {
            if (IsCheckNumber(By.XPath(".//div[@class='_1WZqU PNlAR']")))
            {
                driver.FindElement(By.XPath(".//div[@class='_1WZqU PNlAR']")).Click();
                string selectitem = listBox2.SelectedItem.ToString();
                listBox2.Items.Remove(selectitem);
                timer8.Stop();
                timer6.Start();
            }
            else
            {

                if (listBox2.SelectedItem != null)
                {
                    string selectitem = listBox2.SelectedItem.ToString();
                    listBox3.Items.Add(selectitem);
                    listBox2.Items.Remove(selectitem);
                    C--;
                }
            }
        }