iPhoto photo order

I'm having a bit of trouble with iPhoto. I've just imported a whole load of photos from a folder, and in the folder they were in chronological order. However, when they go into iPhoto, they all get switched around, ie, the newest one is first when I'd like the oldest one to be first. The names of the photos are right (eg, the one I'd like to be first is called 001). Is there anyway of swapping them around without having to do it manually?

Thanks!

 

You're a genius, (and I feel like an idiot), thanks very much!