Supposedly when I click the button "Check Availability!" It will show (next to the button) whether the desired login name exists / otherwise. But my safari doesn't show anything. In Firefox, it does..
Sometimes there's a very brief pop up that closes almost immediately, just to verify a few things with the browser.
However, I think it's probably a similar issue to the Dell online store. I don't know much about web page design, but I don't think it's Flash, could be Java. What does the Activity window say while you're trying this?