Jay Leno checked into a Los Angeles hospital on Thursday with an undisclosed illness, forcing the comedian to cancel a taping of “The Tonight Show” for the first time in his 17-year tenure. Leno's representatives did not say what he was treated for at the hospital, but he is expected to return to work on Monday. “Jay Leno is doing just fine,” NBC said in a statement. “He was kidding around with the hospital staff and running his monologue jokes by the doctors and nurses.” The location of the hospital was not disclosed either. Leno, 58, has not missed a scheduled appearance on “The Tonight Show” since he started hosting it in 1992, except for a show a few years ago in which he traded places with Katie Couric, said NBC spokeswoman Tracy St. Pierre. Conan O'Brien will take over the coveted “Tonight Show” slot on Jun. 1, while Leno will move to his own week-night prime
