You may run into Java security problems with the Web Start option. The Java runtime environment should walk you through setting up an exception if this happens.

You may also download the runnable jar which will allow you to use the SalesFun class in direct unit tests as well as run the application.

Most problems can be worked around by running:

java -jar TestSalesFun.jar

Finally you can download the source file, inspect it, and compile it yourself.

Please let me know if you run into any trouble.