Silverlight XAML Primer 13: Starting and Stopping Animations: Listing 5: Pausing and stopping a Storyboard animation.
function tbPause_Click(sender,args)
{
var animation = slControl.Content.FindName("TextBlockAnimation");
animation.Pause();
}
function tbStop_Click(sender,args)
{
var animation = slControl.Content.FindName("TextBlockAnimation");
animation.Stop();
}