Click here to download Java (it's free)
Then make sure that JavaScript is enabled for your web browser:
For Firefox:
- Open Firefox.
- On the Tools menu, click Options. (Preferences menu if you are using a Mac, and go straight to the Content tab in step 3 below - there are no "options")
- On the Content tab, select Enable JavaScript.
- Click OK.
- Open Internet Explorer.
- On the Tools menu, click Internet Options.
- On the Security tab, click Internet.
- Click Custom Level.
- Scroll down to Active scripting.
- Click Enable.
- Click OK.
- Click Yes.
- Click OK.
- Open Opera.
- On the Tools menu, click Preferences.
- On the Advanced tab, select Content.
- Check the box next to Enable JavaScript.
- Click OK.