How do I know which image is my original when I make a virtual copy?

Question:
If I make a virtual copy, how do I know which is the original and which one is the virtual copy?

Answer:
This is a great question. Of the stack, the first one is always your original. The ones after that will say they are copies in the file name just above the filmstrip. Here is a video to help show you what I am talking about. http://screencast.com/t/5JY3oQaX6ki