IN THE CLASSROOM:

As Cinderella and legions of prom-going girls have known, it’s all about the dress.

Costa Mesa High School’s girls had the chance Saturday to exchange last year’s castoffs for tomorrow’s treasures at the Parent Teacher Student Assn.’s prom and homecoming dress exchange.

The school cafeteria also was lined with booths for cosmetics and jewelry, on offer by area parents.

Diana Moore, a Costa Mesa mom whose seventh-grade daughter, Amanda, attends Costa Mesa Middle School, sold Cookie Lee jewelry at the event.

The dresses ranged from a Mandarin-style Asian gown to a dark blue taffeta rouched mermaid affair. Old styles blended with new — some of the latter still had price tags attached.

Allie Hatch, 15, and her other sophomore friends tried on gowns like a slim, form-fitting black sheath with a large sequined appliqué.

A donated black and crème tulle gown was exchanged for a leopard-print vintage dress.

“Almost everybody who walked in has found a dress,” parent Rachel Kane said; her Arbonne cosmetics booth was popular among the high school kids who came in to look at dresses.

Those who showed up without a dress to exchange paid $10 for the privilege of walking away with a dress of their choice.

All remaining dresses at the end of the day were donated to the Women Helping Women organization, which holds a “Belle of the Ball” event in March for underprivileged girls.

PTSA President Jana Sullivan said the event has benefited from increased marketing, thanks to some new advances the school has made.

“We have a great new tool this year that the school implemented called School Loop,” she said.

The communication method allows parents to get daily updates of their students’ progress, as well as school activities.

“I’ve been involved with PTA for over 10 years now,” Sullivan said. “This is my sixth year on this campus, and there’s a new enthusiasm. The district has really worked hard to make this school the best it can be.”

CANDICE BAKER can be reached at (714) 466-4631 or at candice.baker@latimes.com.