Stephen King trumpeted real books over electronic ones at an appearance the other night to promote his latest, “Under the Dome,” reports The Post’s Frank Scheck. Holding up the massive tome, he asked the audience, “Wouldn’t you want this? It’s nice . . . and if there’s a fly around, he’s gone” — as he slammed the book down. King opined about the Internet (“Everybody bitches about everything”); endless video sequels to his “Children of the Corn” (“Do you know how embarrassing that is?”); and whether his books should be taught in public schools (“I want to be banned!”).