storyboard in beta 2

q1)in beta 2 i cant use storyboard to position objects on canvas 
   Dim sb As Storyboard = New Storyboard

        sb.Duration = dur
        sb.Children.Add(xa)
        sb.Children.Add(ya)
        Storyboard.SetTarget(xa, bb) ';   //set Animation Target
        Storyboard.SetTargetProperty(xa, "(Canvas.Left)") ''error
        Storyboard.SetTarget(ya, bb)
        Storyboard.SetTargetProperty(ya, "(Canvas.Top)") 'error

        LayoutRoot.Resources.Add(sb)
        sb.Begin()

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