UI Controls Silverlight

    xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation' 
    xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'
    xmlns:d='http://schemas.microsoft.com/expression/blend/2008' 
    xmlns:mc='http://schemas.openxmlformats.org/markup-compatibility/2006' 
    mc:Ignorable='d' 
    d:DesignWidth='640' 
    d:DesignHeight='480'>
    
        Source="http://localhost/A.wmv" 
      AutoPlay="True" x:Name="medElem" Opacity="0.0"/>
                    VerticalAlignment="Stretch" BorderBrush="Black" BorderThickness="3">