[jQuery] page-first.gif

Hi!
I have a problem. How do I do to find page-first.gif image reference?
I have a jQuery test application an it run successfully but the really
application that I need to run doesn't show images like page-
first.gif, page-first-disabled.gif, page-last.gif, etc.
Where is the reference to those images or what I must to do to fix my
problem?
Regards!