Cannot view my edited photos on iPhoto
I have uploaded my holiday photos onto iPhoto and i edited all of them. However, I think the original copies may have been deleted? I dont know if this can happen but it has meant that the now edited photos apparently don't exist and i cannot do anything with them. When i click on them it comes up with a triangle with a ! in it. I cannot do anything to the photos (eg. copy or use them as a desktop background or send them). I do have copies on my sd cards but will i have to delete these photos and upload and edit again. If so how can i stop the problem from happening again?
iPhoto '11