She hopes 'Enough' will inspire victims to tap their inner strength

Jennifer Lopez has taken on an intense assignment in her new film "Enough." It's a psychological thriller that keeps you on the edge of your seat.

She plays an abused wife who tries to get help through legal channels. When that approach fails, she runs away from home with her 4-year-old daughter, then turns the tables on her womanizing husband.

Knowing that she has to return for a custody hearing, the wife decides she's "had enough" and becomes determined to learn how to stand up for her rights.

"I [studied] Krav Maga, considered to be one of the world's most effective and deadly martial arts," says Ms. Lopez, a singer who has also starred in "Selena," "The Cell," and "The Wedding Planner."

"It was developed by the Israeli army to teach women how to defend themselves. I worked for weeks with Wade Allen, a martial-arts expert. Then we devised special moves that would show specifically how this particular woman would defend herself. We even added some street-fighting methods."

Billy Campbell plays her abusive husband. His character is light years away from the nice guy he plays on ABC's family drama "Once and Again." Director Michael Apted selected him because audiences wouldn't expect him to be so vicious.

It took 10 days to film one of the final fight scenes, which proved physically taxing for the actors.

"In the movie, the circumstances are very extreme, although such fights do happen in real life," Lopez says. "For me, [the film] does have a message.... No matter how bad the situation gets, you have the power to change it or to get out of it. The only person you can look to is yourself, and that's what the character does. She almost becomes a female Rocky."

Because the story line of "Enough" is aggressive, Lopez thoroughly researched her role. "I talked with people, read books, searched the Internet," she says. "I think it is easy for someone, looking from the outside, to be judgmental. I didn't want to judge anyone."

She found that lament is a common thread among abuse victims.

They wonder, " 'How did I get into this situation,' " she says. "When you are in a negative cycle with someone you love who has betrayed you, you have to emotionally come to terms with it, and then find the power to get out of it. Then you have to see if you can stay away."

J. Lo, as she is often called, especially likes the film's message: that regardless of circumstance, people can muster the power to change things, she says.

Even after the picture wrapped, it turns out that Lopez had one more thing to do. Producer Irwin Winkler called her and asked her to write and perform a theme song for the movie.

"I was looking at my next script ... when I suddenly had to shift gears," she says with a sigh. "I began to think back over the 'Enough' script.

"Then I walked into the den where my husband, Cris Judd, was playing chords on the piano. He had made up a melody that was so beautiful. It sounded like a movie theme ... it had this lovely haunting quality about it. I said to myself, 'I can write the lyrics.' "

She memorized the notes and thought deeply about the aim of the film and what the heroine endured. Then she began writing the theme song "Alive."

"The more I wrote, the more grateful I felt for being here ... and being alive," Lopez says. "It isn't the type of music I usually write, but things have a weird way of happening naturally ... when they're supposed to, and I feel this song was meant for the movie."

Only one other actress has written and performed a song for her own film: Barbra Streisand for "A Star is Born" in 1976.

Lopez, who grew up in the Bronx and is the middle of three daughters, sees a basic difference between making music and acting. "Music is a personal matter. When you record it, you like it or you don't," she says. "Movies are more of a collaborative affair. You do the best you can, and then it's out of your control."

She is now working on her next film, "Uptown Girl," in which she plays a stay-at-home mom with a small daughter who lives in the Bronx. It's much less harrowing than "Enough."

Lopez has also been busy managing her new line of clothing, working with her father to run Madres, her new family-style restaurant in Pasadena, Calif., and preparing her next album.

"What keeps things under control is that I take time to rest," she says, laughing. "Make no mistake, I love what I do, and I like being with my loved ones. That is enough for Cris and me."