[Catalyst] Checking client browsers, best approach?

[Ryan]

OK, here is what I need to do.  I'm writing a reservation system for a
hotel and I have some cool features in mind for the process but they
require javascript and "newer" browsers. What I was planning on doing is
creating the bare-bones pages that work in any browser, no JS just all
server calls etc...then I want to go back and insert the new stuff where
it's appropriate but only for the people that can handle it.  I was
thinking of having a landing page(default or something) that ran some
tests to see if that could fail. Then I thought it might be easier in the
begin function to just check browsers and set a variable in the stash if
they can handle the new stuff or not. What's the best way to go about
doing this, should I just scan the req variables that come in and make my
decision on that or does Catalyst have something better?