I am using Lightroom 4 to manage my photo files. Images are filed in folders with sub folders. When I first transfered my files to a universal Lightroom folder there were no images in main folders. All images were in sub folders. Now somehow it has changed so that all the images in the sub folders are mirrored in the main folder. For example if I had 10 sub folders each containing 10 images,the main folder shows 100 images and they display when I click on it. If I try to eliminate the images on main folder, they are also removed from the sub folder. My question is,how do I eliminate the images in the main folder without removing them from the sub folders ?