I've put a green box on the due east part of the horizon--see that it is on the far left, click on it! I found the eastern horizon as described here.
If that doesn't work, probably your web browser's "imagemap" is screwed up.
You can click here to advance to the next page.
You might also email to report the problem. If possible report the name of the
browser (Netscape, Internet Explorer, etc.) and computer type (PC, Mac, SGI, etc.).