It is hard for Varaj to sit still and talk, his eyes are always darting about looking for things to scavenge. He finds it hard to concentrate when he goes to the school at lunchtime. His mind is always racing. The Christian teachers have asked him to tell the foreigners his story. So he does.

When his family left Salem, hundreds of miles to the south of India in Tamil Nadu, his father promised that the streets of Mumbai were paved with gold. Varaj now knows what the streets of Mumbai are really made of because that is where he works every day rag-picking - mud and excrement, broken glass, paper, plastic and occasionally bits of metal. Varaj has never found any gold. Often when he wades through the sewage he cuts open his feet and his skin erupts.

One day he found a large piece of metal, so he earned 500 rupees ($12) that week. But often it is less than 250 rupees for working from dawn until midday and from 4pm until dark. It is Varaj's ambition to become a policeman. Then he could arrest the rag masters who cheat him every day. In his wildest dreams he wants to become a government minister because then he could get anything he wanted, a big house for his family and he could give jobs to his friends so they would not have to rag pick or beg.

Varaj keeps only 10 rupees a day for himself; the rest goes to support the family. What is left of them. His father has gone. Mother says he went home to Tamil Nadu because he was sick but Varaj sometimes wonders whether his father has not just found another shack in another part of Mumbai, where he keeps on drinking the few rupees he earns. Three of his four sisters have married and left, his little brother is dead. So it is down to Varaj and his big brother to support the family. Sometimes his mother will go out rag-picking, dragging her twisted leg behind her, but at other times she stays inside in the dark and drinks.

Varaj's home by the water pipeline is far too small to receive his visitors. The family has to pay 300 rupees a month in rent for a nine-feet by seven-feet room with a back wall made from beaten and flattened-out tin cans. The roof is just bits of plastic held up by a thick bamboo pole. There is a gap between the top of the wall and the roof so Varaj can hear every grunt and cry that comes from next door. The family needs to keep paying back the money borrowed from debt collectors for his sisters' weddings and to find more for drink. The debts never seem to get any smaller.

Every few months men in uniforms come and tear down all the homes and repair the crude hole though which local families get water out of the pipeline. The next day the landlord's men are back and homes are built again. A new hole is bored in the water pipe, and the electricity is tapped again. The men wash on one side of the pipe, amid the stench left by those who have relieved themselves in the same place. On the far side of the pipe the women bathe in their clothes for modesty's sake.

After he has talked for nearly two hours Jessica asks Varaj if he is happy. He thinks it is a strange question. At the pipeline everyone speaks the same language, they all live the same way so nobody is jealous of anybody else. Outside he hears his friends playing, so he answers her "Yes" and then like a flash he is gone. Tomorrow he has to work again.

"I don't think any of the children knew who I was," joked Jessica later. "They thought I was a foreign teacher. I'm glad they didn't know me because that meant they talked to me honestly and openly. I realise that I wouldn't be here to listen to them except for my celebrity. That is the paradox. Celebrity has to be good for something."

Jessica Lange was in India working on a documentary film for the charity campaign LISTEN. The campaign brings together film stars, music stars, dignitaries, film directors, writers and visual artists in a bid to raise awareness and money for the world's most disadvantaged children. The intention is to generate more than $90 million. But in many ways the money, which will go to pre-designated children's charity projects, is secondary to the major issue. LISTEN is about listening to the rights and needs of children. The campaign culminates in a globally broadcast media event.

It is determined to make the world much more aware of the problems children suffer from around the world. "75% of the world's children are no better off today than they were 1,000 years ago," says Executive Producer Tony Hollingsworth. "We know what the problems are. We know what the solutions are. The problem is we are not listening."

Jessica visited two projects in Mumbai. Both are attempting to give education to poor children. The Pipeline project is run by the World Vision Network of Care which is trying to get Tamil children back into some sort of education so they can get a better job. In India there are 80 million children who work rather than attend school.

Two days later she visited the SHED project (run by Save The Children) in Dhavari, which with its two-and-a-half million inhabitants is the biggest slum in the world. There, children sick with tuberculosis and other potentially fatal diseases are given medicine and gently eased back into education.

Jessica, accompanied by her 18-year-old daughter Shura, found her first experiences in India hard to absorb. "Here poverty is everywhere," she says, "every street you go down, every corner you turn, every alleyway, it is all pervasive. But even then there are levels and differences. In some places, the children were ill but they all went to school, they had a place to go, they had a sense of purpose. The pipeline children have never been to school, they think about it but they don't have the possibility of going because of economics. To me, speaking to these children in the last few days it has struck me how much we take it for granted. When education is denied a child for whatever reason we are depriving them of something sacred to their childhood.

"For me to talk to these children has been a God-given gift. There is nothing I love more than children, which is why I came in the first place. I think it is our duty, children are dependent upon us, we have a responsibility to the generations that are coming. We cannot limit ourselves to our own families, our own communities. We have to address this as far as we possibly can. What we really owe the earth and what we owe the children is to make a colossal effort in the new millennium to try to make things better for them."