As there is no Timer control item in the WPF I have used DispatcherTimer class in my code to show the countdown that starts from 1 and ticks every second.....but what I want to do and where I am having problem is that with Minute and second time display pannel I want to display a fast changing time beshide second like 00:00:XX "XX" being fast changing value.....

Here is what I have done till now:
int a = 1;
private void dispatcherTimer_Tick(object sender, EventArgs e)
            timerTextblock.Text = a.ToString()+" : "+DateTime.Now.Millisecond.ToString();

private void Window_Loaded(object sender, RoutedEventArgs e)
            DispatcherTimer dispatcherTimer = new DispatcherTimer();

            dispatcherTimer.Tick += new EventHandler(dispatcherTimer_Tick);

            dispatcherTimer.Interval = new TimeSpan(0, 0, 1);


please note that i need not to be that accurate under the second, I just want it visually there as it gives some sense of urgency........