New to Java

Hi,
I'm trying to compile some code, and there are still multiple errors. Some of them involve the package javax.jnlp which the author was trying to import into a certain java file. The specific error on the line "import javax.jnlp.*;" the error is "The import javax.jnlp cannot be resolved".

When trying to figure out the problem, I read that the need to include this package explicitly was eliminated between JDK versions 1.4 and 1.5. I have version 1.5, but the author of the code wrote it a while back (some 5-7 years ago?) and told me that I will need to figure out what changes are necessary to bring it up to date. Regardless of the need to include this package (and whether the import is commented out or not), I am unable to use classes that are supposed to be in the package, such as BasicService, ServiceManager, and UnavailableServiceException. On lines using these classes, error messages say that they can't be resolved. What do I need to do to be able to use this package?

Also, are there are any other glaring JDK version differences between ~5 years ago and now, which I should look out for?

Thanks for your help,
Roteph