Acceptiong RequestDispatcher.forward() requests

[Asim Khaja]

I have a page that implments the IExternalPage interface, that based on
certain parameters forward the user to another Tapestry Page that has a form
in it.  This pages in involved by doing a rd.forward from antoher servelet

RequestDispatcher rd =
                   
_mobileWebPageServletContext.getRequestDispatcher(http://blah.com/BLAH/app?service=external&page=Home&sp=S1&sp=S2);

                *// Forward to requested URL
*                *if* (rd != *null*)
                   rd.forward(mwpsr, resp);




 But when i submit the form i get a Session has expired error.