Calling JSP (from Tapestry)

I've built an "ExternalPage" in Tapestry, and I'm able to access the session
and retrieve variables, as well as pass in variables from the JSP side. Now
I'm trying to get back.

I'm trying to write out links back to JSP. I tried using GenericLink and the
URL "/nav.jsp?pg=bundle". This builds the link as
"http://localhost/nav.jsp?pg=bundle", however, I need to be able to control
whether it is https vs. http, and it needs to add in the weblogic session
tracking info (without specifying the domain, preferably). How do you do
this in Tapestry?

Thanks,
Joel