Or stop being lazy and write a native
Windows (I presume they're on Windows since you mentioned Silverlight. Otherwise, replace "Windows" with whatever OS they use) application that will offer even
less limitation on how it's presented, be way faster for them to use, and support offline storage and data synchronisation for in case their network/Internet connection goes down.
Hell, if you're really stuck on the Silverlight-style UI, use WPF. It's Silverlight on mega-steroids!
P.S. Copying this post to the clipboard before I click Post, in case it times out again...

P.P.S It's not PAB, it's PAWAWNAWBMA(WAAC)*
* People Against Web Apps When Native Apps Would Be More Appropriate (Which is Almost Always the Case)