I have a problem with data binding map controls with the slider on my XAML page. I'm not sure what I am missing but when I run the problem and tilt the slider left or right, nothing happens. I set the ZoomLevel for the map to have a data binding of two way so it'll update the map animation instantly based on the slider's value change, but nothing is happening, what am I doing wrong? I've seen some data binding correlating with C# code such as changing the font size of a textblock but some aren't, so I figured that here, it should work without using any C# code, but directly within XAML code itself.

XAML code:

Code XAML:
    FontFamily="{StaticResource PhoneFontFamilyNormal}"
    FontSize="{StaticResource PhoneFontSizeNormal}"
    Foreground="{StaticResource PhoneForegroundBrush}"
    SupportedOrientations="Portrait" Orientation="Portrait"
    <!--LayoutRoot is the root grid where all page content is placed-->
    <Grid x:Name="LayoutRoot" Background="Transparent">
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
            To localize the displayed strings copy their values to appropriately named
            keys in the app's neutral language resource file (AppResources.resx) then
            replace the hard-coded text value between the attributes' quotation marks
            with the binding clause whose path points to that string name.
            For example:
                Text="{Binding Path=LocalizedResources.ApplicationTitle, Source={StaticResource LocalizedStrings}}"
            This binding points to the template's string resource named "ApplicationTitle".
            Adding supported languages in the Project Properties tab will create a
            new resx file per language that can carry the translated values of your
            UI strings. The binding in these examples will cause the value of the
            attributes to be drawn from the .resx file that matches the
            CurrentUICulture of the app at run time.
        <!--Uncomment to see an alignment grid to help ensure your controls are
            aligned on common boundaries.  The image has a top margin of -32px to
            account for the System Tray. Set this to 0 (or remove the margin altogether)
            if the System Tray is hidden.
            Before shipping remove this XAML and the image itself.-->
        <!--<Image Source="/Assets/AlignmentGrid.png" VerticalAlignment="Top" Height="800" Width="480" Margin="0,-32,0,0" Grid.Row="0" Grid.RowSpan="2" IsHitTestVisible="False" />-->
        <!--TitlePanel contains the name of the application and page title-->
        <StackPanel x:Name="TitlePanel" Grid.Row="0" Margin="12,17,0,28">
            <TextBlock Text="MAP DEMO" Style="{StaticResource PhoneTextNormalStyle}" Margin="12,0"/>
            <TextBlock Text="Map Control" Margin="9,-7,0,0" Style="{StaticResource PhoneTextTitle1Style}"/>
        <Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
            <maps:Map Name="myMap" ZoomLevel="{Binding zoomSldr.Value, ElementName=zoomSldr, Mode=TwoWay}" HorizontalAlignment="Left" Margin="10,0,0,0" VerticalAlignment="Top" Height="348" Width="436"/>
                    <ColumnDefinition Width="160"/>
                    <ColumnDefinition Width="160"/>
                    <ColumnDefinition Width="160*"/>
                <RepeatButton Name="btnHeading" Click="btnHeading_Click" Content="heading" HorizontalAlignment="Stretch" Margin="0,347,0,0" VerticalAlignment="Top" Width="160" Grid.Column="0"/>
                <Button Name="btnMode" Click="btnMode_Click" Content="mode" HorizontalAlignment="Stretch" Margin="0,347,0,0" VerticalAlignment="Top" Width="160" Grid.Column="1"/>
                <Button Name="btnColor" Click="btnColor_Click" Content="color" HorizontalAlignment="Stretch" Margin="0,347,0,0" VerticalAlignment="Top" RenderTransformOrigin="2.089,0.564" Grid.Column="2"/>
                    <ColumnDefinition Width="160"/>
                    <ColumnDefinition Width="300*"/>
                    <RowDefinition Height="50"/>
                    <RowDefinition Height="50"/>
                <TextBlock HorizontalAlignment="Left" Margin="10,424,0,0" TextWrapping="Wrap" Text="zoom" VerticalAlignment="Top"/>
                <Slider Name="zoomSldr"  Value="1" Minimum="1" Maximum="20" SmallChange="1" LargeChange="10" HorizontalAlignment="Left" Margin="1,408,0,0" VerticalAlignment="Top" Width="295" Grid.Column="1" Height="85"/>
                <TextBlock HorizontalAlignment="Left" Margin="10,475,0,0" TextWrapping="Wrap" Text="pitch" VerticalAlignment="Top"/>
                <Slider Name="pitchSldr" HorizontalAlignment="Left" Margin="1,460,0,0" VerticalAlignment="Top" Width="295" Grid.Column="1" Height="85"/>