Welcome to FT..
There are some threads on this if you search.
http://www.flyertalk.com/forums/show...kipping+flight
If your original flight was a oneway you are fine but if there are more legs you are trying to use from the original itinerary you are not.If you don't show up all of the later flights will be canceled. You will have to refare if you want to use the later legs of the trip.