13 Going on 30

OK, we knew all of that from not only every body-switching movie ever made but from every wishing story ever told. And yes, there are all the expected collisions between the lives of the 13 and 30-year-olds. Jenna raises her hand to be called on in a meeting and responds "Ew, gross!" to the advances of her boyfriend. And darned if she won't be the only one to come up with those save-the-day ideas for the magazine. But the script has some bright moments and there is also some nicely understated humor. The only possible environment where a 13-year-old's sense of appropriate hair and fashion might be considered acceptable for an adult is, of course, in the offices of a fashion magazine, where the more outrageous something is, the more everyone else will feel that they are the ones who are missing something for not having it themselves. Jenna writes her name at the top of the page at a meeting and keeps her office files in middle-school folders.

Ruffalo, as always, adds class and sweetness to the boyfriend role, and has impressive delicacy in providing romantic interest for someone who is, after all, emotionally just 13 years old. But what makes this one work is Garner, who is enormously touching and hilarious as the 13-year-old living in the body and life of a 30-year-old. Playing a child in an adult body gives her license to show every emotion without any pretense of sophistication. She is wonderfully open and vulnerable but she handles it lightly and with a lot of charm. And she captures it all perfectly, from her panic at not understanding what is going on to her rapture as she selects clothes and makeup for her grown-up self as though dressing a Barbie. Garner even gets the walk of a 13-year-old just right, from the shoulders, not the hips. And the look on her face as she does the dance to "Thriller" is so winning you won't just smile with her; you might just start to dance along a little.