Topic: thumb area registration?

Hi all-

i have a gallery setup with only 1, long row of thumbnails.  using the fixed gallery, and the thumb area x/y, i have centered the row of thumbs below the large image.  works fine.  But now i would like to add more photos from time to time - which requires me to have to manually re-center the thumb area depending on how many images are in the gallery.  Is there i way i can change the thumb area from the left registration to the center registration, so i wouldn't have to change the thumb area each time i want to add more photos?  please let me know if you lead me in the right direction.

Thanks!  - jeff