long runTicks = DateTime.Now.Ticks;
        System.Threading.Timer tmr = null;

        public Form1()
        {
            InitializeComponent();

            tmr = new System.Threading.Timer(new System.Threading.TimerCallback(TimerTicking), null, 0, 1000);
        }

        private void Form1_FormClosed(object sender, FormClosedEventArgs e)
        {
            if (tmr != null)
            {
                tmr.Dispose();
            }
        }

        delegate void timerAllReady(string timeData);

        private void TimerTicking(object callBack)
        {
            TimeSpan ts = new TimeSpan(DateTime.Now.Ticks - runTicks);
            this.Invoke(new timerAllReady(TimeWriting), new object[] { string.Concat(ts.TotalHours.ToString("00"), ":",
                                                                                     ts.Minutes.ToString("0#"), ":",
                                                                                     ts.Seconds.ToString("0#")) });
        }

        private void TimeWriting(string timeData)
        {
            textBox1.Text = timeData;
        }