After three of his novels became motion pictures scripted by other writers (The World According to Garp, Hotel New Hampshire and A Prayer for Owen Meany, which was rechristened on screen as Simon Birch), and two of his own screenplays languished unproduced, Irving finally got his chance to adapt one of his novels to film. The focus of this slim, eloquent memoir is Irving's 13-year struggle to bring The Cider House Rules to the big screen, and its passage through the hands of various producers, four different directors and numerous rewrites. Backtracking to illuminate the origin of the novel's pro-abortion stance, Irving introduces readers to his grandfather, an obstetrician and gynecologist, and to the history of abortion. (Abortions didn't become illegal throughout the U.S. until 1846, when physicians sought to take the procedure--and financial rewards--out of the hands of midwives, Irving reveals.) He also offers a fascinating and detailed look at how he trimmed his huge novel into a workable screenplay. Although he professes to love the final product, Irving details each scene and line that was cut as the film was edited down to two hours. While he claims to be pleased with the screen treatments of his previous novels, he is disappointingly silent on the subject of Simon Birch (he refused the filmmakers the use of the protagonist's name and also insisted that the screen credit state that the film was ""Suggested by the novel""). 32 pages of photographs. (Nov.) FYI: The Cider House Rules, starring Tobey McGuire, Michael Caine and Erykah Badu, opens Nov. 24.