Whats wrong with my code? Any reference missing?

Question

I have been trying to add the navigation tool that will simply zoom in and zoom out. Push left and right using the click of the mouse.

I'm using in the Silverlight, Visual Studio 2010.

The XAML file contains the following:

<esri:Navigation Margin="5" HorizontalAlignment="Right" VerticalAlignment="Bottom"
 Map="{Binding ElementName=MyMap}">
 </esri:Navigation>

The C# file contains the following:

private void MyMap(object sender, RoutedEventArgs e)
    {
        MyMap.Focus();
    }

I have added the reference dll file : ESRI.ArcGIS.Client.Toolkit

Though the navigator is visible on the map. But unable to function. Please assist the same.