this has nothing whatsoever to do with the appserver.
Check your IDE documentation, or ask in their support forum if you don't understand the documentation and they happen to understand you.
As jwenting mentioned, this question is more related to NetBeans IDE than JBoss application server or EJB3. You might probably get an answer in their forums. Here's one post (which came up when i googled) which says why JavaEE5 is not available while integrating JBoss-4.2 with NetBeans http://www.nabble.com/How-to-create-EJB3-project-in-Netbeans-5.5.1---6.0.1--td15949951.html