I really can't tell from the photo. There are a large number of yellow or yellowish damsels around, which are often confused in the aquarium literature - and the same holds generally for damsels. Yours looks to be either a Stegastes or Pomacentrus species, but I would need a better photo to be sure. The photo posted by 54seaweed also appears to be a Pomacentrus species (most likely P. moluccensis) ... Amblyglyphidodon species tend to be deeper bodied and have a forked tail. (Also, A. aureus lacks the dark spot on the pectoral base.)
Tony