My 1992 integra with manual trans. is stuck in neutral!

What is your question?

Driving, in gear, the car suddenly popped out of gear. I couldnt get it into any gear after that. When I shift the shifter, it feels like its going into gear, but its not. Tried shutting car off etc to put it into gear. Nothing works to get it into gear. A problem with the clutch assemblyor the clutch itself wouldnt prevent it from going into gear when its shut down, would it? It makes no senseto me. The fork that goes inside the trans is in place and it feels like its going thru the gears wheni shift with shifter. But, its not!! I dont know where to start or what to do! I dont want to replace a bunch of parts without being sure of what the prodlem is. Any ideas?!!