http://blogs.msdn.com/b/randyoakley/archive/2008/11/30/using-javascript-to-control-expression-encoder-sp1-silverlight-2-templates.aspxThe Silverlight 2 player templates included with Expression Encoder SP1 were released without enabling scripting from JavaScript. Here is how to customize the Silverlight 2 templates to allow scripting. 1) In Expression Encoder SP1 selecten-USTelligent Evolution Platform Developer Build (Build: 5.6.50428.7875)