Gregory A. Harris used to think he would spend his days after high school taking orders for corned beef and pastrami sandwiches behind a deli counter someplace.

"When you first come out of high school, you just take whatever you can get," he reasoned.

Instead, at age 20, he works full time in the blood services department at Howard University Hospital as a phlebotomist, taking about 40 samples of blood from patients every day.

The tall, soft-spoken young man, who grew up in rural Calvert County, Md., credits his turnaround to the D.C. Summer Youth Employment Program, which each year sends 60 to 80 teenagers to Howard University Hospital. Harris joined the program as a high school sophomore in 1986.

"I was what you call one of those street people too. Just going out to go-gos and having fun. The attitude was, 'I don't care,' " he said. "When I started working there full time, it just showed me a new way. It made me think about things."

Although the jobs program has its share of failures and critics, Harris is among those who say the program has made a real difference in their lives. Pearlie McDaniel, the hospital's coordinator of community resources, says the program offers youngsters options and teaches them how to function in a professional environment.

"I like to get youngsters to come back so they can continue to build on their experience," she said. "They do learn some marketable skills."

Harris, she said, is one of those who has been able to use the experience as a springboard to advanced education or a career in the health field.

Harris said his father, a truck driver, and mother, a delicatessen manager, could not afford to send him to college. Also, he said, he felt obligated to help his family out financially because of staggering medical bills incurred for treatment of his 18-year-old brother's severe asthma.

So at age 15, he moved away from home to live with relatives in the District so he could qualify for the city's summer job program.

At the time, it was something to do and a convenient way to earn pocket money, he said.

That first summer, he was responsible for wheeling patients around the hospital. The next summer he was asked back and assigned to the blood services department, transporting specimens to laboratories.

McDaniel said she tries to woo bright and energetic youngsters to her program, and cites Harris as one of her success stories.

Two years ago, after his high school graduation, Harris was offered a full-time job at the hospital. He was taught the techniques of withdrawing blood, which he said he practiced on a water-filled rubber glove. The supervisors also arranged for Harris to take a job-related class at Howard University. Today he makes about $18,500 a year.

Now his whole life has changed, he said. He no longer hangs out late at night with friends, because he has to be at work by 8 a.m. He has adopted a much more serious approach to life, he said.

Partying "takes a toll on your body. You feel it," he said. "I have more responsibility now."

His supervisors at the hospital plan to take advantage of his newfound maturity this summer by making him a supervisor in the summer youth program. He is now responsible for overseeing students assigned to his department.

"It's going to be easy because I'm the same age as they are and I can relate to what they need and what they don't need," he said. He said he also feels good about paying back a program that has been good to him. "It helps a lot of young people get off the street," he said.