Running .cla files in Firefox

[uberkermitt]

I have this programming book which comes with a CD-ROM - the CD contains java applets as a teaching aid. I have run the applets from Windows but when I fire up the CD on my Gentoo machine, and point Firefox at the applets, nothing happens. I know Java works in my browser, so I don't get why these won't work. As I mentioned before, they work ok in Windows (I would just use Windows to look at them now, except that I don't own a copy of Windows anymore).

The files in question have a .cla extension. There is a main index page that you start with (html) with links to each chapter's exercises. When you click on the link, it takes you to another html page with the jave applet embedded.

Any thoughts would be appreciated.