I believe if you don't have Java enabled, when you try to get into chat I believe you will get an error message saying you don't have Java enabled. From your other post it sounds like that didn't happen so you probably have Java enabled.

Another way to find out is to find the Options option in your browser.

I can't tell you exactly how to do that since it's different for different browsers and browser versions.

In mine, for example, it's under the Tools option, then Options on the pull-down menu. Then if you poke around there you should be able to see a check box that says if Java is enabled.

If Java is not enabled and if you have a PC, all you need to do is follow the instructions on this page:
http://www.java.com/en/download/windows_ie.jsp

This allows you to download and install the FREE - Java Runtime Environment
It's very straightforward.