SmoothLS

I took my car to the car wash on Monday and they must have moved the passenger seat to vacuum, etc. but for some reason the seat is now stuck. It's not a power seat and the lever to move it back and forth seems to be working fine (but then how would I know since I rarely sit there). The seat just doesn't move more than four inches from front to back. No idea why and I don't see anything preventing it from moving. Some other postings said to check for loose springs, etc. but everything looks fine under there. Any ideas? Thanks.