How do I stop a running video using Blend/WPF?

Question

How to stop a video after playing 10 sec. And the video slider will also stop.

thanks.

My coding:

        if (threeA.IsSelected == true)
        {

        Video.Source = new Uri(@".\step_3.wmv", UriKind.Relative);
        Video.Play();

        descriptionText.Text = "Stepping out.";

        // When the video play until 10sec, both the video and time slider will also stop //
        // User must click on the next treeitemview in order to play the next part of the video //

        }