(12A, 94 mins): Starring Ryan Reynolds, Amy Smart, Anna Faris. Directed by Roger Kumble

In the film When Harry Met Sally, bachelor Harry Burns (Billy Crystal) famously tells his soul mate Sally Albright (Meg Ryan): "Men and women can't be friends because the sex part always gets in the way."

His pessimistic summary of gender relations inspired countless magazine articles and now it informs the film Just Friends, a romantic comedy about two lonely people whose high school relationship foundered when one of them dared to say "I love you".

Back in 1995, when All-4-One's ballad I Swear became a lament for every lovesick teenager, Chris Baxter (Reynolds) was overweight, shy and didn't stand a hope of being part of the in-crowd.

He was also madly in love with his best friend, beautiful cheerleader Jamie Palamino (Smart), who crushed his dreams by admitting she loved him - but only like a brother.

Humiliated in front of his jeering classmates, Chris vowed revenge.

Ten years since that fateful graduation party, Chris has lost half his body mass, polished his chat-up technique and is a successful Los Angeles record company executive.

He's at the top of his game and has just been assigned the unenviable task of working with spoilt socialite Samantha James (Faris), who is bidding for pop stardom.

By chance, Chris and Samantha find themselves stranded in New Jersey and they decide to pay a quick visit to his mother (Julie Hagerty) and brother (Chris Marquette).

Memories flood back and Chris is stunned to find Jamie working behind the bar in town, re-igniting his long-buried desires.

Chris makes it his mission to win the one woman who got away.

Only he has a rival for her affections: Former high school classmate Dusty Dinkleman (Chris Klein), now a kind-hearted paramedic who plays the guitar and has written a song in Jamie's honour.

Just Friends follows Chris's efforts to woo Jamie, while fending off Samantha, who happens to be one of his many ex-flames and would dearly like him to stoke her fire.

The amusing Nineties' prologue, which features Reynolds in a fat suit, is too brief to give us any real insight into Chris's personality and features predictable high school jokes.

He's painted as a superficial caricature, so when we flash forward to 2005, we struggle to root for the now svelte Chris trying to win the girl, because we have little emotional investment in him or his happiness.

Smart exudes a fresh-faced, girl next-door appeal but it's Faris who shoplifts every scene.

She is incredibly entertaining as the deranged socialite turned pin-up turned pop sensation, whose voracious sexual appetite is dwarfed only by her over-inflated sense of self-importance.

A comic set piece - the destruction of a Christmas light display - merits a chuckle but on the whole, Just Friends is just average.