Gregory Peck and Mary Badham in 'To Kill a Mockingbird.' (Photofest)

Another movie night at the White House, but this time one of the classics: President Obama and the American Film Institute are hosting a screening of “To Kill a Mockingbird” Thursday afternoon in the executive mansion’s family theater to commemorate the movie’s 50th anniversary. Expected guests include Mary Badham, the former child star who played Scout, as well as the family of the late Gregory Peck — who won an Oscar for his portrayal of civil rights-minded lawyer Atticus Finch; today would have been his 96th birthday. Not on the RSVP list: the novel’s reclusive author Harper Lee , last seen around here when she accepted the Presidential Medal of Freedom from President Bush in 2007. But in a statement, the writer said she’s proud the movie, which she calls “the best translation of a book to film ever made,” is being recognized at the White House. Obama is also taping an introduction for a Saturday night broadcast of the movie on USA Network.