I am not sure that I follow your file hierachy diagram, but it looks as if you have the web.xml located at WEB-IFN/classes/web.xml - it should be at WEB-INF/web.xml.
P.S. - it would have been better if you ran "jar -tf Helloapp.war" (assuming you hvae a WAR file, and not an exploded diectory) and posted the response.
Thank you very much Peter this solvwd my problem.
But I just want to tell you I've beeing follwing the example on page 24 Figure 1.10 of your book 'JBoss in Action'
We used Eclipse to generate the directory/file hierarchy diagrams, so knowing how Eclipse (or even NetBeans) visualizes that hierarchy within the project explorer helps. I can see that in some cases the lines between the directories and their included files and subdirectories are somewhat light in the printed book, but if you use the PDF version and zoom in to 200% then the lines show up clearly.