InDesign CS
Windows XP Pro

10 files make up one book, each file has two master pages

Master page A is common to the book (all files have the same Master page A)

Master page B is unique to each document in the book, yet based off of Master A

So, is there a way to have one Master Page A that all of the files in the book use? I want to insure that all of the files are indeed using an identical Master page A, and that any changes to Master A will only have to be made once.

We had a change to Master page A, and the solution was to drag the changed master to each document, delete the old Master A and set Master B to be based off of New master A, then proof each document to insure the change was correct... phew.