I'm guessing this may be fairly basic but I can't find out how to do it!

I'm writing a book. Each chapter is a separate Word document. When I change some text in one of the chapters, I want that change to be copied into a bigger document that contains the whole manuscript (ie all the chapters).

Is that possible?

By the way, though I use Word 2007, I save documents as Word 97-2003 so that they can be seen correctly on a much older computer at work.

Would be very grateful for any help.

Steve