insert new page style

edit

My rather complex book was imported into Writer and has Convert 1, Convert 2, etc, to describe the page Style for each chapter. For some reason, in two cases, the Chapters have the same Convert #, such that they both have the same Headers. How can I rename the second page Style or insert a new page Style so as to be able to correctly label the headers in the second chapter? The page styles available on the menu are not suitable as they again assign identical headers to two chapters. I need a new page Style to hold the headers for that chapter. Also, in one instance the header in a sequential page style persists in retaining the header from the previous page style on the first page.