The Java Plug-In (1.5.10 or higher for Windows; 1.3.1 or higher for Macintosh) is required in order to use the registration program. If you are having difficulty registering, please take these steps:
Windows users can download the Java plug-in here. Macintosh users should use the Software Update feature (available under the Apple menu) to check that they have the most up-to-date version of Java for their Mac.
Instructions on how to enable Java in your browser are located here.