So bookmarked position on wp8 player timeline

Topics: Windows Phone 8
Nov 7, 2013 at 9:23 AM
I need to provide three customize buttons on player.
1st button : on click set a bookmark (show a dot, circle etc ) on timeline bar at current position of video.
2nd button: Move current position to next bookmarked point.
3rd button: Move back to previous bookmarked point.

Once user sets the bookmark, at later stage when he plays same video get list of bookmark(time on timeline) from server. I need to show those bookmarked point on timeline.

My problem is that I am not able to show these bookmark using VisualMarker. Below is the code I have written in page behind cs file.
      VisualMarker visualMarker = new VisualMarker();
        visualMarker.IsSeekable = true;
        visualMarker.Time = TimeSpan.FromMinutes(2);
Can any body suggest why this is not working? Similar code when I used in wp7 application using TimeLineMarker was working fine.

Many many thanks in advance for any help.