A newbie question

[Jack Dong]

hi, I am a newbie to use cocoon,and get a question. I use cocoon 2.1 and tomcat 4.0.4 beta3. when i type http://localhost:8080/cocoon, it's right. but when i copy the "hello world" sample  from "$CATALINA_HOME/webapps/cocoon/sample/hello-world" to"$CATALINA_HOME/webapps/cocoon/hello-world" and type http://localhost:8080/cocoon/hello-world/hello.html it response a error page,that note"resource not found", why and what relation have between main sitemap and substitute sitemap?     by the way, what mean like "{1}.rdf ,{2}.rdf"?   thinks advance.