HILARY Duff, who plays the title character on the Disney Channel's "Lizzie McGuire," gets to strut her stuff as both Everygirl and pop singer in this big-screen adaptation of the 2-year-old hit series.

As in the show, animated sequences by Debra Solomon and Tapehouse Toons give sparky life to the conflict between Lizzie's inner resolve and outward hesitations. The clever cartoon bits go a long way toward making Lizzie a regular girl; while Duff is a capable, spirited and ingratiating performer, she's perhaps a tad too sophisticated to be believable as the girl next door.

But that will be no drawback for her faithful fans. Director Jim Fall has orchestrated Lizzie's dream vacation with energy and humor, and girls 9-14 will thrill at the protagonist's cool clothes and Vespa rides through the streets of Rome. For the grown-ups accompanying the core audience, scriptwriters Susan Estelle Jansen, Ed Decter and John J. Strauss have

After a humiliating display of klutziness at her junior high graduation -- videotape of which Lizzie's budding evil genius of a younger brother, Matt (Jake Thomas), promptly sends to Diane Sawyer -- Lizzie and a select group of classmates embark on a two-week trip to "La Citta Eternal," as their pit bull of a chaperone, Miss

impersonate his missing singing partner, Isabella (Duff), Lizzie's dark-haired twin, at the upcoming International Music Video Awards. In one of the story's lapses in logic that won't much matter to anybody who's enjoying the lark, no one particularly notices that Isabella-gone-blond now speaks only English, American-style at that.

injected the proceedings with enough dry wit (considerably upping the series' quotient of that ingredient) and genuine emotion to make the film appealing. It should prove a solid family draw at the box office.

ungermeyer (Alex Borstein), likes to call it.

Before you can say "Gidget Goes to Rome," dreamy 17-year-old pop idol Paolo (Yani Gellman) is romancing Lizzie (chastely, of course). He also convinces her to

Archrival Kate (Ashlie Brillault), a girl unpleasantly bent on being popular, turns out to be Lizzie's ally in her game of deception, and her best friend, Gordo (Adam Lamberg), covers for her with Miss ungermeyer at his own peril. Lamberg is terrific as the soulfuleyed Gordo, who, despite his feelings for Lizzie, encourages her adventures with Paolo. Back home, Matt follows his sister's exploits on the Internet and, with the help of his young Lady Macbeth of a partner in crime, Melina (Carly Schroeder), plots to get her busted by their folks.

The film embodies kids' view of adults as well-meaning but hopelessly clueless or mean-spirited but hopelessly clueless. Without getting preachy, the story wraps with a nice comeuppance, making points about friendship, trust and the crucial fact of life that sometimes Prince Charming is a jerk. Jerzy Zielinski photographs Rome at its postcard-romantic best, and the teen-target song selections are exuberant without being dumb or cloying.