How is it that you are trying to look for them?
They're in the game files.
For extracting:
http://www.wowpedia.org/Viewing_Bliz...interface_code
If you want to just view these as .png files so you can see what they are and their paths:
http://wowprogramming.com/utils/artbrowser
__________________
"You'd be surprised how many people violate this simple principle every day of their lives and try to fit square pegs into round holes, ignoring the clear reality that Things Are As They Are." -Benjamin Hoff,
The Tao of Pooh