Sadly, the teleportation prototype actually duplicated the user, forcing the originals to have to kill themselves every time the machine was used to avoid any confusion.
Any programmer will tell you the copy is just a second instance of the first person's type. It exists separately in spacetime (analogous to memory space). :)
It's from a fantastic movie that would be completely ruined if I told you the name; so refer to the comment below if you don't mind the huge spoiler...
