When the December issue of Sassy magazine hits the newsstands, the slick, full-page cosmetic ad won’t look much like the one that Susan Greeley slapped together at her home in Old Town last month.

Then again, the 17-year-old Old Town High School senior hasn’t been quite the same either since she won Cover Girl’s “Ad Wiz for a Day” contest held last month in conjunction with Sassy, a teen magazine.

“Everything has been just a blur,” Greeley said after returning from an expenses-paid tour of New York to watch her winning drawing produced by a Madison Avenue agency.

Greeley’s ad, which will be used to promote an eyeliner pencil, was chosen by Cover Girl from more than 1,600 entries from young copywriters from across the country.

“Susan’s copy and layout hit the nail right on the head, in terms of creativity and demonstrating an understanding of the Cover Girl spirit,” Cover Girl Vice President Charles Busta said in announcing the contest winner.

Greeley, the daughter of Paul and Bernice Greeley, admitted that she did not know what the Cover Girl image was supposed to be when she came across a notice for the contest in the magazine.

“They said they wanted something professional and clever,” Greeley recalled. “So I drew a close-up of a woman’s face, with her hair swept back and the focus on the eyes. I wrote some body copy and added the slogan, `There’s Never a Dull Moment,” since it was an eyeliner pencil that never needs sharpening.”

That slogan could also have been used to describe Greeley’s life since she got the call from New York informing her that she had won.

“When they told me, I couldn’t think straight and I started hyperventilating,” she said with a chuckle. “I think I scared my mother a little. My parents haven’t even seen the ad I did. I didn’t think it was any good so I never showed it to anybody.”

Greeley and her older sister, Missy Tasker, were flown to New York on Sept. 11 by the ad agency that handles the Cover Girl account. They stayed at the Intercontinental Hotel, shopped at Saks Fifth Avenue, and were chauffeured to the Hard Rock Cafe and the Broadway musical, “Cats.”

“I was just awestruck by it all,” Greeley said, “The buildings were so big, and there so many people of different races and everybody was just going at a thousand miles an hour.”

On Sept. 12, Greeley and her sister attended a photo session with Renee Jeffus, a top teen model who will appear in the ad. Jeffus then posed with Greeley, who was interviewed for a story in the magazine’s December issue.

“I thought I’d be shoved off into the background, but they made me a part of everything,” Greeley said. “After watching Renee’s photo session, I don’t think I’m the model type. Everybody was always poking into her face with makeup. I think I’m better behind the scenes.

She said the whirlwind experience has opened her eyes to the future.

“I’m glad to be home and finally relax,” said Greeley, who hopes to study art after she graduates from high school. “But I already miss New York and I realize how much I love advertising. I think that’s the life for me.”