Images not showing, application frame greyed out

Another plea for help. I was working on a file and hit something by accident on my keyboard. All images I was working on disappeared. Usually the name appears at the top and I can click on it to bring that image up. The application frame is greyed out and I am completely lost. I can see the files at the bottom of the Window drop down menu but can't figure out why they are not showing at the top. If I click on a single image it will come up but I want them all up the top where they usually are.   TIA