Add a custom JDK to Netbeans 6.9.1

I'm trying to add a custom JDK to Netbeans 6.9.1 on OSX 10.6.5. The JDK is just a collection of classes created for leJOS, a Java package for the Lego NXT robot. I can't jus开发者_JAVA百科t add the classes for this JDK to the existing Java JDK because there are a few nasty mismatches between things that are classes in one and interfaces in the other. When I select the "Add Platform..." option from the Tools > Java Platforms menu I get a file chooser dialog. If I point this at some existing JDK I can can select "Next" and move on. If I try to do this with the jar files for leJOS I get no such option. Can anyone tell me what file this dialogue box is actually looking for, and how I can create one for an arbitrary collection of classes?

cheers, Nick

File/Folder Structure of your JDK is not conforming the Standard.

see http://download.oracle.com/javase/1.5.0/docs/tooldocs/linux/jdkfiles.html