It is useful to think of the Silverlight object as having its own object model. Within that object model, some properties, methods and events are directly accessible, such as onError, Settings, Source, InitParameters and CreateObject.
In addition, the Silverlight object has a sub-object named content and a second sub-object named settings
The content sub-object
it is common to access properties of the content sub-object, especially as this is how you access FindName().
However other useful properties of the content sub-object include ActualHeight. ActualWidth, CreateFromXaml, FullScreen and OnResize, among others.
The settings sub-object
Perhaps the most important properties of the settings sub-object are Background and Windowless. This sub-object also includes MaxFrameRate and a few others.
All of this is well documented under the topic Silverlight Object Models and Scripting to the Silverlight Plug-In in the Silverlight 1.0 Documentation. Scroll down to Scripting to the Silverlight Plug-In where you'll find three very useful tables