Run a helloWorld in NetBeans

Hi, When i make a helloworld programme http://java.sun.com/docs/books/tutorial/getStarted/cupojava/netbeans.html
why can i not run it, i mean i understand i have to run it through netbeans which works, but say if i wanted to show it to a mate how would i show it to him? Will i have to open netbeans and then run it?

Thanks

Just type java <path to class file>.class and it should run.

Joe