LEWISTON – Mike Jalbert needed no booze.

The Lewiston High School junior, dressed in a white suit that made him look like a musician on an awards show red carpet, beamed as he held his girlfriend’s hand. She, too, looked ready for the prom’s paparazzi in a black dress that complemented her boyfriend’s attire.

“I’m sure people will drink,” Jalbert said. “It’s a classy event, and people think alcohol’s part of that. I don’t need it.”

That’s what Paul Amnott, an assistant principal at Lewiston High School, wanted to hear.

Armed with a hand-held booze detector – a $350 passive alcohol sensor – Amnott watched from a distance Saturday as Lewiston High School juniors and seniors pulled up to their prom in family cars, stretch limousines and even a posh bus.

During the first hour, when most of the expected 450 teens arrived, he never had to use the much-publicized device.

“It’s not like we’re standing at the door, testing people as they come in,” Amnott said. “Our mission was to create a deterrence. It’s worked so far.”

Last week, school officials made announcements about the device, which works like a crude breath tester. Letters were sent to parents.

Drunken kids would face a 10-day suspension, they were told.

The prom attendees heard the message.

Some teens, such as Jalbert, said they liked having the device present. Drunken kids might cause a ruckus, or worse, get into an accident later.

Others figured their classmates would merely plan parties later in the evening – where they’d make up for drinking time lost during the prom.

The assistant principal’s little black box has been the hot topic of conversation ever since the warnings were issued, senior Emily Torres said.

“You’d have to be really clueless to have missed it,” Torres said. “She guessed some kids would be caught. Drinking is traditional. That’s high school.”

However, junior Brandon Samson guessed the punishment would be too extreme for many seniors to flaunt the rules. After all, a suspension might mean being banned from graduation, he said.

“A lot of people are worried,” Samson said.

Parents, too, were worried.

Claire Durgin, whose son Nate attended the prom, said she was happy to keep the party chem-free. After all, the teens’ memories of the special night will be richer for it.

However, mom Pauline Gilbert worried that the decision to test the kids put more pressure on parents to make sure their kids stayed clean at the after-prom parties.

Before her son went to the prom, she asked him again and again about his plans. She even made him charge his cell phone, just so she could be sure to reach him anytime during the night.

“You talk to them the best you can,” she said. “And you worry.”

However, their behavior at the beginning of the night impressed several people, including Robert Fernald, a chauffeur who drove 18 kids in his new, luxury bus.

“I was worried,” he said. “You hear the stories. But they were very well-behaved.”

On the way to the prom, they sat in his bus, watched his big-screen TV and drank water and sparkling cider.