If project is a Dinamic Web Project, JBDS should include all required libs and all modification in web.xml (as described here: http://www.jboss.org/file-access/default/members/resteasy/freezone/docs/1.1-RC1/userguide/html_single/index.html#Installation_Configuration)
If project is a Seam Web Project, include required libs as described here: http://docs.jboss.com/seam/2.1.1.GA/reference/en-US/html_single/#d0e21523