In 1974, author Michael Crichton wrote a screenplay based on his own experiences as a resident physician in a busy hospital emergency room. The screenplay went nowhere and Crichton focused on other topics. In 1990, he published the novel Jurassic Park, and in 1993 began a collaboration with director Steven Spielberg on the film adaptation of the book. Crichton and Spielberg then turned to ER, but decided to film the story as a two-hour pilot for a television series rather than as a feature film. Spielberg's Amblin Entertainment provided John Wells as the show's executive producer. The script used to shoot the pilot was virtually unchanged from what Crichton had written in 1974. The only substantive changes made by the producers in 1994 were that the Susan Lewis character became a woman and