This one is not so much a tutorial as it is an annotated example. You'll need to download the program source code file (Authorware 5.1 format) from the link below. The program has instructions on the needed setup, and then you can examine the program itself to see exactly how it works. For questions, contact the author.
Here's the source code. (You might have to "right-click" on the link to download the file (less than 50Kb.))
Have fun!