There's a table called "book" and it contains list of book names and another table called "authors_author_books" and which is contains author_id, book_id that assigned authors to the particular book. And there's another table called author which contains all registered author_id and name.
When i select a book from drop down menu, i listed all registered authors to the left hand side multiple drop down box and all assigned authors to the right multiple drop down box. when i'm assigning a new author to the existing book which has already assigned to author,I have to remove the assigned user from left drop down box which is contaning registered authors
