Here's an example of abysmal user interface design. That's not surprising; I see this crap every day. But this is from Apple! (it's part of setting up the "Genius" service in iTunes)
Is the second box for your password or does it have something to do with AOL? And what on earth does the red arrow mean?
This could easily have been fixed by putting the two radio buttons to select whether to use your Apple iTunes Store ID or your AOL ID across the top horizontally, keeping this selection visually separate from the entry of your user ID and password.