add child

I am setting up a site where the user will create a book from a link located in a side menu block titled " add book". Clicking on the link will open a content type that has a form I want the user to fill out. I am using fields provided in Drupal 7 to create the form. When they click on save the new book gets created using the module book made simple and it is added to a book block visible in the side menu. What I need to do is also create child pages under this new book.