The movie was probably made in the 90's and stars three kids. (Two boys, one girl.) I believe the girl is a blond Winona Ryder. There was also this creepy old neighbor who kept track of time and knew everything about the kids. One of the kids, named Devon steals the other boy's computer book and travels through time? The two remaining kids travel through time (To the 1800's) to get him, running into these time travel guys in suits that try to kill 'em. Meanwhile, Devon is trying to sell the book for loads of money in the 1880's. At the end, they are all saved and go back to the present.
I REALLY NEED THIS ASAP!!