New York ? When Liz Murray didn’t have a bed, she and a friend would sometimes go to a diner in the Bronx, pool their change to buy french fries with gravy and cheese, and take naps with their heads resting on the table.

Since then, the 22-year-old has been to Harvard University and back again in a real-life story of willpower and determination that has inspired a television movie.

When “Homeless to Harvard: The Liz Murray Story” premieres on Lifetime Television at 8 p.m. today, Murray wants viewers to come away with the notion that changing your life is “as simple as making a decision.”

“I want them to feel empowered, to really take charge,” she said, nibbling on a veggie burger at the same diner, near the elevated tracks of the No. 4 train.

Murray’s story has a happy ending, but it isn’t simple. It winds through streets and stairwells, group homes and subway stations, and touches upon deeply emotional territory.

So when a special about her life on ABC’s “20/20” led to movie offers, she was told to be skeptical.

“I’d been warned so much about these ‘movie people,”‘ said Murray, dressed in jeans and sneakers, her dark hair pulled back into a ponytail. “I haven’t regretted it at all.”

The movie stars Thora Birch as Liz, and Kelly Lynch as her mother, and follows Murray on a journey that begins in the Bronx apartment where she lived in poverty as a child.

Murray is now living her new life in the old neighborhood, in her own apartment around the corner from the diner. She relates wrenching bits of her past matter-of-factly, fixing a strong, steady gaze on the listener.

Her parents were addicted to drugs, and she grew up watching their money disappear. By the time she was 15, her mother was sick with AIDS, and her father was living in a shelter.

Determined to stay out of the child welfare system but with no stable home, she and her friend Chris — played in the movie by Makyla Smith — packed their bags and set out on their own. There were nights they crashed at friends’ apartments or rode the subway until dawn, and nights they slept on a rooftop landing, using flannel shirts as blankets.

Seated in the same Bronx diner where she sat with a screenwriter to script the movie Homeless

In 1996, Murray’s mother died, and she vowed to change her life. She returned to high school and stayed to study long after classes ended, never telling her teachers that she was homeless for fear she would be sent to a group home.

Murray managed to graduate from the Humanities Preparatory School in two years. She won a New York Times scholarship and was accepted to Harvard.

To make “Homeless to Harvard,” she sat down with screenwriter Ronni Kern and recounted her story for three days.

“This was not a story that we had to fictionalize to make it more compelling or more dramatic,” said Trevor Walton, senior vice president for movies at Lifetime.

Murray is credited as a co-executive producer and has a cameo as a social worker.

She says it was crucial for her to make sure her parents were portrayed with sensitivity. The movie strives to reflect her complicated relationship with them, opening with a monologue delivered by Birch that echoes her own words:

“I loved my mother so much. She was a drug addict. She was an alcoholic. She was legally blind. She was a schizophrenic. But I never forgot that she loved me, even if she did — all the time, all the time, all the time.”

Murray decided to leave Harvard several months ago, and now lives with a roommate, close to her friend Chris, her sister, and her father, Peter Finnerty, who is HIV positive and has been struggling with complications of Hepatitis C.

“I need to feel more grounded than I did,” she said. “I didn’t feel grounded there.”

She has been taking care of her father, working on a memoir and giving motivational speeches, and plans to continue her college education with film courses over the summer.