Hello,
This is a newbie question. Any help would be MUCH appreciated.

I am using JBoss. My servlet, HelloServlet, prints a simple Hello
statement. I create a hello.war file with files

welcome.html
META-INF/Manifest.mf
WEB-INF/web.xml
WEB-INF/classes/hello/HelloServlet.class

web.xml is as -

<?xml version="1.0"?>

<!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web
Application 2.3//EN" "http://java.sun.com/dtd/web-app_2_3.dtd" >

<web-app>
<servlet>
<servlet-name>HelloServlet</servlet-name>
<servlet-class>hello.HelloServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>HelloServlet</servlet-name>
<url-pattern>/HelloServlet</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>welcome.html</welcome-file>
</welcome-file-list>
</web-app>

I place the hello.war in the jboss/server/default/deploy directory.
JBoss starts up fine saying that the war file has been deployed.
In my browser, I type
http://localhost:8080/hello/welcome.html
This works fine.

However when I do
http://localhost:8080/hello/HelloServlet

I get
"Internal Server Error
The server encountered an internal error (Internal Server Error) that
prevented it from fulfilling this request"
..and so on

I have been following the SAMS Teach yourself EJB book.

Further, I have also tried putting my files in jboss/catalina/webapps
The structure is as

webapps/helloapp/welcome.html
webapps/helloapp/META-INF
webapps/helloapp/WEB-INF/web.xml
webapps/helloapp/WEB-INF/classes/hello/HelloServlet.class

At the browser, I do
http://localhost:8080/helloapp/HelloServlet and get

No Context configured to process this request
The server encountered an internal error (No Context configured to
process this request) that prevented it from fulfilling this request.

Please help. Thanks, DG