And the for the application, with new 5.0.27 tomcat version , each application should have its own context file in $CATALINA_HOME/conf/catalina/localhost/.
This is as per info in the url http://jakarta.apache.org/tomcat/tomcat-5.0-doc/config/context.html (Please note that for tomcat 5.x, unlike tomcat 4.x, it is NOT recommended to place <Context> elements directly in the server.xml file. Instead, put them in the META-INF/context.xml directory of your WAR file or the conf directory as described above)
I have created FirstProject.xml as my context file and placed in $CATALINA_HOME\conf\catalina\localhost\ and the contents are
Context configuration file for the Tomcat Administration Web App
<!-- Uncomment this Valve to limit access to the Admin app to localhost for obvious security reasons. Allow may be a comma-separated list of hosts (or even regular expressions). <Valve className="org.apache.catalina.valves.RemoteAddrValve" allow="127.0.0.1"/> -->