JavaScript uses this name to refer to this particular graphic slot. Now normally I would completely avoid such an obnoxious action by an animated GIF as you see on the Site Map page but consider this, it only animates when you provoke it by rolling your mouse cursor over it. It is not constantly nagging like a forth wife at the corner of your eyeballs to leave whatever important work they are doing at the time to glance at it. So go nuts, do something fun and wild but remember you don't want too much extra baggage of very big GIF files. Keep in mind that just by using rollovers, you have doubled the download time of your graphics, making them animated rollovers is even worse .
Animated rollovers are easy to do.
That is all you have do to add cool looking JavaScript rollovers without blowing up a browser that is unable to display them. Of course it can get a lot more complicated than this but this is the basic guts of even the most complicated of rollovers, if you can get a grasp of this you will easily understand the rest. The hardest part of this is coming up with an idea then creating your graphic display. The easiest part of this is the fact that you can just copy and paste the code up there into your web page.