Need to update my photo gallery online

Hi,

Don't know if I'm writing in the right section or not but here's my question.

I'm writing a website in Java which has a photo gallery created in Flash. I want to know how am I supposed to add my new uploaded photos to the flash gallery. I know I can do it by XML but the thing is how to check in my website that new photos are available? Sorry maybe it's a dumb question but it seems that I'm out of any clue right now. I've developed websites in Java before but never had to have a dynamic photo gallery. Thanks