In Documentation.chm written following thing :
Add a new Jscript file to your root of the web application named “fblogin.js”
Open fblogin.js and replace the entire file with the content from Appendix B
Edit the fblogin.js’ silverlightPluginId variable value to match the ID of the Silverlight plug-in in your hosting web page.
This variable is used to locate the plug-in during authentication.
Where This Appendix B ?????? In what document ???