Silverlight Media Player

<UserControl x:Class="MediaPlayer.HorizontalGallery" x:Name="ucHGallery"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
    Width="400" Height="50">
    <Grid x:Name="LayoutRoot" Background="White" >
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="15" />
            <ColumnDefinition />
            <ColumnDefinition Width="15"/>
        </Grid.ColumnDefinitions>
        <Grid.Resources>
            <Storyboard x:Name="hideMenu">
                <DoubleAnimation  By=".1" From="0" To="1" Storyboard.TargetProperty="Opacity"
                                Storyboard.TargetName="rect" Duration="0:0:1" 
                                Completed="DoubleAnimation_Completed" >
                </DoubleAnimation>
            </Storyboard>
            <Storyboard x:Name="showMenu">
                <DoubleAnimation  By=".1" From="1" To="0" Storyboard.TargetProperty="Opacity"
                                 Storyboard.TargetName="rect" Duration="0:0:1"
                                 Completed="DoubleAnimation_Completed_1" >
                </DoubleAnimation>
            </Storyboard>
        </Grid.Resources>
        <Button Grid.Column="0" Content="&lt;" Click="Button_LClick"></Button>
        <Button Grid.Column="2" Content="&gt;" Click="Button_RClick"></Button>
        <Canvas Grid.Column="1" Background="LightBlue"  >
            <StackPanel Orientation="Horizontal" x:Name="imgGallery"  >

            </StackPanel>
            <Rectangle x:Name="rect" Fill="LightGray" Visibility="Collapsed" Height="50" Opacity="0" Width="370">
            </Rectangle>
        </Canvas>
    </Grid>
</UserControl>