NEW YORK, NY (AP).- Best-selling author Michael Crichton approached art in the same way he did his writing — through extensive research — but also by developing close friendships with many of the artists whose works he collected. The popular thriller writer died in 2008 leaving behind such blockbusters as “Jurassic Park,” ”The Andromeda Strain” and the TV series “ER.” But he also left a 20th century art collection that features some of pop art’s best known artists, including Jasper Johns, Roy Lichtenstein and Claes Oldenburg. Crichton’s family is selling about 80 percent of the collection at Christie’s auction house in New York on May 11-12. Among the highlights is Jasper Johns’ “Flag,” a rendition of the American flag that Crichton bought from the artist in 1974, and which decorated the writer’s Beverly Hills bedroom. It was last