Buttons without instance name

Hi,
I am very new to FlashMX2004 (actually Flash altegether) and even using Forums to post questions, but here goes…
I found this site kiupa.com by fluke yesterday while trying to find tutorials. While looking at the mx2004 tut “Menu with Slider” by Bryan Arciniega, I see each button is created individually and not instanced from one button. Why?
If this is a stupid question - sorry!
Regards,
Woot