private void buttonMarkStartN_Click(object sender, RoutedEventArgs e)
{
Button btn = (Button)sender;
markStart = Player.Time + new TimeSpan(0, 0, Convert.ToInt32(((string)btn.Content).Substring(0, ((string)btn.Content).Length - 1)));
//markStart = Player.Time - new TimeSpan(0, 0, diyProp.GetTimeChange((diyProp)sender));
FreshTime();
}