I'm looking for the name of a movie I watched over ten years ago. I remember the following things about it: It was a time-travel action movie, in which a group of teenagers used a device with one or two "electrified glass balls" to travel through time. One of the scenes involved dinosaurs, I think. Another scene could have involved a Korean/Japanese army or something. I have wanted to see this film for the last five years, but I just can't remember what it's called... Don't remember anything about the actors, just that the protaganists were a group of teenagers.