title: Display the running time of part of a program in a label
body: <p>I am trying to have a label display the time it takes the user to complete a task which starts at 00:00:00 and goes up in shown millisecond increments from there.
  So far I have this:</p>
  <pre><code>    private void startTimer()
      {
          stopWatch.Start();
          Dispatcher.BeginInvoke(DispatcherPriority.Render, new ThreadStart(ShowElapsedTime));
      }
      void ShowElapsedTime()
      {
          TimeSpan ts = stopWatch.Elapsed;
          lblTime.Text = String.Format(&quot;{0:00}:{1:00}.{2:00}&quot;, ts.Minutes, ts.Seconds, ts.Milliseconds / 10);
      }
  </code></pre>
  <p><code>startTimer();</code> is called on a button click</p>
  <p>Can someone point me in the right direction?</p>