What does single mom-turned-best-selling author J.K. Rowling think of the film adaptation of her Harry Potter and the Sorcerer's Stone? Though the movie's $220 million take thus far shows audiences approve, the writer's opinion worried producer David Heyman (The Daytrippers) most. After all, consider the embarrassing publicity that results when such heavyweight scribes as Anne Rice and Stephen King rail against the big-screen versions of their books!

"That [first] screening was very, very scary," admits Heyman. "[Rowling] watched it with 50 of her closest friends [so] there was not only her, but her friends to contend with." His fears were put to rest, he says, when "she came down the aisle and sat next to me with tears on her face. [She] threw her arms around me and said, 'Thank you very much. I loved it, I loved it, I loved it.'"

A similar happy moment occurred when Rowling was sent a tape of Potter star Daniel Radcliffe during the casting process. Recalls Heyman: "She called me and said, 'Thank you. I feel like I've been reunited with my long-lost son.'"

Both Heyman and director Chris Columbus — who currently are shooting the sequel, Harry Potter and the Chamber of Secrets — credit Rowling with much of the film's success. "Keeping her involved was key to me to keeping the books alive," says Columbus. "For every novel, she has another novel's worth of information about the characters and about their pasts and all this great information for me, for the actors, for the production designers."

Also a relief, notes Columbus, is that "[Rowling] was aware that there were certain restrictions of film and certain things that you needed to change." Adds Heyman: "Jo never dictated to us what we should do. She was always there as counsel. She had no casting approval, but she gave her suggestions and we took [them] and we cast those people."