Sending SMS with background worker

namespace CSMsystem
{
    
    public partial class adminwelcome : Page
    {
        private string[] ports;
        ...............
        ...............
        ..............
        private readonly BackgroundWorker worker = new BackgroundWorker();
        public adminwelcome()
        {
            InitializeComponent();
            loaduserbut();
            worker.DoWork += sendingSMS;
            worker.RunWorkerCompleted += smsCompleted;

        }
 

        public void loaduserbut()
        {
            loadPorts();
            ..........
            ..........
            ..............
            if (status == "thankYou")
            {
                
                worker.RunWorkerAsync();
                ...........
                ...........
                ...........
            }
            else if (status == "comments")
            {
               ..............
               ...............
               ............ 
            }
            else if (status == "final")
            {
                .....................
                ................
            }
            
        }
        ...................
        ......................
        ......................
        ....................
        //Loading ports
        private void loadPorts()
        {
            ports = new string[3];
            ports = SerialPort.GetPortNames();
        }
        //sendSMS
        private void sendingSMS(object sender, DoWorkEventArgs e)
        {
            SmsClass sm = new SmsClass(ports[0]);
            try
            {
                foreach (MobileDtl_Base mobBase in adminwelcome.mobilNumList)
                {
                    sm.Opens();
                    //sendSMS(mobBase.MobileNo.ToString());
                    sm.sendSms("0" + mobBase.MobileNo.ToString(), "There is a feedback from a customer :" + custName + ", R.O.NUM :" + roNum);
                    sm.Closes();
                   System.Threading.Thread.Sleep(1000);
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }
        //
        private void smsCompleted(object sender,
                                       RunWorkerCompletedEventArgs e)
        {
            MessageBox.Show("Messages are sent !!");
        }

    }
}