1. User requests page so server builds page
2. server sends page to client and client scripts execute
3. silverlight objects are executed

So …

In your aspx page html you put the standard object tag with this in it :

depending on requirements you can either edit this object tag on the server or the client.

1 Of the params I pass in is a “StartingControl” which in the App.Xaml.cs file I do this with :

void Application_Startup(object sender, StartupEventArgs e)
{
switch(e.InitParams["StartupControl"])
{
case “Control1″ :
this.RootVisual = new Control1();
break;
….
}
}

This gives you switching functionality before the silverlight object is loaded.

Combine the 2 samples and you can make whatever changes you need at any point.