Compilation dvd using re-authoring

[markis]

One of the great tools of dvd shrink is the slide-bar in the re-author application which allows you to edit and view at the same time parts of a film that you would want to re-author.Say for example,I wanted to re-author 20 mins from one dvd,40 mins from another,30 mins from another, and say 30 mins from another to make a compilation dvd, but wanted to use the slide-bar tool so I could view and be precise about what was being re-authored;I've tried a few attempts but it does not seem to allow it.