http://www.asp.net/learn/ajax-videos/video-172.aspx
you are right about ajax javascript or (jquery-available in asp.net mvc only) you do use script manager to work on the html dom. along with javascript etc
Remember silverlight essentially is a html table
It works on the client side,,,,
http://msdn.microsoft.com/en-us/library/cc645076(VS.95).aspx working with html dom
Silverlight currently in the web edition works with wcf rest sql as a web service
you can use wpf for the intranet version http://windowsclient.net/
I hoped I explained this better and I wanted to show you exactly how it works....