in which file can i find the loading and next button images.

Hi all,
I would be thankful if someone could help me displaying the loading image and the “next picture” image in lightbox (ie when the images are in full screen mode after clicking on thumbnail).
Also note that the website was earlier running on localhost and has now been shifted to a web hoster.

I guess its because the address of the ‘loading’image file has not changed after the server address was changed. If anyone can help me locate the address for that, it would be great.

also if I would like to change the loading spiral image to something else where should I change the source file.
thanks in advance.

http://wordpress.org/plugins/nextgen-gallery/