Unable to start Tomcat 6.x when Mac OS X 10.6 is boot up

Question

I am using Mac OS X 10.6 and installed MAMP and Tomcat.

My Tomcat is installed in /Users/(userID)/Tomcat

I can start Tomcat server in Terminal without a problem

But it cannot be started automatically when Mac OS X is boot up.

I put a file org.apache.tomcat.plist in /Library/LaunchDaemons

Disabled Label org.apache.tomcat ProgramArguments /Users/henryfok/Tomcat/bin/startup.sh RunAtLoad

Any hint ?