package book with Extendscript

I found a thread on this and went to this site...

http://blogs.adobe.com/techcomm/2011/07/create-a-book-packager-using-e xtendscript.html

But....I am still unsure on how to use it. I see I have extenscript in our CS5 suite. But I don't see an archive script.

Thanks for the help!

ls