2000 Frontier 4cyl PCV valve location?

My father has a 2000 Frontier, 4cyl and we can't seem to make out where the pcv valve is in this thing? We've been looking at the Chilton book for days and still can't make sense of where the hell it is? Can anyone enlighten us????

Thanks

Every time i buy a new car i always go to a part store to see if they have parts for it like tune up parts and pcv valves.Stuff like that for later on.From what i was told it has a crank case vent but no pcv valve but mine is a 2002. if there is a tube running from the valve cover area and screwed in its probably a ccv vent but if theres not one running to the valve cover most likely vented some were else and does not need one.