The question of calling JavaScript functions from Silverlight seems to come up quite often and there are solutions to the problem. But one answer I have not seen yet is to use the HtmlPage.Window.Eval method. This method is simply a pass-through to the Eval method in JavaScript on the browser end. It might not be an appropriate solution in all cases, but it's always nice to have options!
1: // C# Code
2: HtmlPage.Window.Eval(string.Format("doSomething('{0}');", "hello there!"));
1: // JavaScript Code
2: function doSomething(message) {
3: alert(message);
4: }