If a sitcom episode from the TGIF line-up was crossed with a commercial from MTV, you’d get this movie, a genial half-hour story stretched out to movie length through the insertion of lots and lots of music for the 11- 16 crowd, who will line up to buy the soundtrack album. It is no coincidence that the name of the movie was changed to the name of Britney Spears’ current hit song.

The plot would fit into an old episode of “Gidget.” High school seniors Nicole (Melissa Joan Hart) and her next-door-neighbor and childhood pal Chase (Adrian Grenier) are now barely speaking. They travel in different crowds. She is filled with team spirit, loves to cheer on the school basketball team, and is working hard to make the school’s 100th anniversary dance a big success. Chase is a rebel, protesting the mindless conformity of his classmates, too cool to support anything at school. When Nicole is unsuccessful in getting basketball star Brian to the big dance, and Chase is dumped by his girlfriend Dulcie for not being as cool as a college boy who is busy protesting the use of animals in lab tests, they agree to pretend to be dating, to see if they can make their respective heartthrobs jealous.

Nicole gives Chase a makeover at Gap, and then they each visit the other’s turf. They are surprised to find themselves enjoying each others’ environments and friends, and enjoying each other. It turns out that they are the ones who get jealous, when Brian and Dulcie take the bait. And their friends, too, learn to judge by appearances.

There is no particular subtlety or insight in the movie, but it is undeniably fun to watch. Grenier, in particular, has real charm (though I preferred his tousled curls to the post-makeover hairstyle). And the movie addresses real issues about the tendency of high school kids to categorize themselves according to clearly defined extremes and to stick with friends who reinforce their interests, attitudes, and appearance.

Parents should know that there is a good deal of drinking by teens in the movie. Both Nicole and Chase react to setbacks by getting drunk at parties. The attitude of the kids in the movie seems to be that as long as they have a designated driver, there is no reason kids should not drink. Nicole is also betrayed by a friend, who tells Brian that he should be interested in her because she is willing to have sex with him. Later, Nicole insults her by calling her “easy.” A drunken boy attempts to force his intentions on a girl, and, when she refuses, he is abusive and insulting. While there are other sexual references, the behavior of the kids is limited to some romantic kissing. Parents may want to discuss the issue of cliques and snobbery in school, the importance of feeling liked for what one considers most important about oneself, the dangers of trying to manipulate others, and the difficulty of living with a single parent. Parents should also warn kids not to follow the example of one character, who arranges a real-life encounter with a cyber-date. It might not turn out as well as the one in the movie.