Middle school is the prelude to high school, and high school lasts for the rest of your life, so you better find a way to cope with it.

Greg Heffley (Zachary Gordon, "Four Christmases"), the wimpy kid of "Diary of a Wimpy Kid," recognizes that middle school is the turning point. He thinks that half the kids in it are babies and the other half are morons, not realizing that all are a combination of both categories.

On his first day of middle school, his older brother, Rodrick (Devon Bostick, "Saw VI"), advises him to fly under the radar: Don't raise your hand, don't make eye contact, don't talk, and don't stand out in any way. But Greg wants to be the most popular kid in school by the end of the year, and in order to achieve that, he decides to get involved in those activities that get your picture in the yearbook.

He tries out for wrestling and gets his spandex kicked by "” gasp, choke "” a girl, the horrible Patty Ferrell (newcomer Laine MacNeil), who's been whomping up on him since kindergarten. Note that she bears a striking resemblance to Patty McCormack as the psychopathic Rhoda in "The Bad Seed."

In fact, just about everywhere Greg turns, Patty is there to make his life a living hell. He also runs afoul of three dropouts whose truck he scratches, sadistic teachers and, in one case, his own success when his singing voice turns out to be so high, the music teacher wants to cast him as Dorothy in "The Wizard of Oz," the role for which Patty has a yen.
But Greg's biggest problem is his lifelong best friend, the rotund and perennially youthful Rowley Jefferson (Robert Capron, "Bride Wars").

Rowley hasn't got a guileful bone in his body, while Greg is certain he has to become someone he isn't in order to gain popularity. It's the age-old problem of middle school: Do you stay true to yourself or do you force an unnatural change in order to appear older? And what do you do when your best friend still acts and thinks like a kid when you want to become a teen?

Despite the fact that this adaptation of a kid's novel by Jeff Kinney is aimed at the junior-high demographic, director Thor Freudenthal ("Hotel for Dogs") sees the universal dilemmas in the basic situations and has produced a movie that works for kids and adults who remember what it was like "” and still is "” to feel out of place and awkward.

The movie is funny and doesn't stress the sentimentality that makes most kid flicks instantly forgettable.

The supporting cast includes Rachael Harris ("The Hangover") and Steve Zahn ("A Perfect Getaway") as Ma and Pa Heffley, Grayson Russell ("Talladega Nights") as hapless