STEPHEN LEWIS explores the dangers lurking on the Internet for unwary teenagers.

CORONATION Street's mixed-up teen mum, Sarah Louise Platt, is about to get into trouble again.

In an hour long episode on Sunday night, followed by an extra half-hour special later the same evening, millions of Corrie fans will watch as the 14-year-old mum plunges herself needlessly into danger when she arranges to team up with a chatroom "friend" she met on the Internet.

Sarah thinks that "Gary", her online friend, is a teenage boy about her own age.

In fact, he's a very adult Internet stalker who's been "grooming" her on the net. He encourages her to phone him - and before she knows it, she has agreed to pay him a visit at his home, despite warnings from her friend Candice.

She is surprised when the door is answered by a good-looking man in his 30s. He claims he's Gary's dad - but it soon becomes clear to Sarah the man she's sharing a drink with is in fact a pervert who preys on young girls in the net.

Things turn nasty when the horrified teenager tries to escape - and Gary refuses to let her go.

It's a nightmare storyline that will have mums and dads up and down the country rushing to check just what it is that their teenage sons and daughters are getting up to when they spend all those hours on line.

No one is suggesting that youngsters should be forbidden from using the Internet. It can be a brilliant educational tool - as well as a place for teenagers to meet and chat online while in the safety of their own homes. But that doesn't mean there isn't a need for care.

"The Internet has opened up a new world for children - cyberspace can be educative, informative and most of all fun," says Home Office minister and chairwoman of the government's Child Protection Taskforce Beverley Hughes. "But, as the Coronation Street storyline shows, we must all be alive to the potential for paedophiles to abuse the trust that children place in this new world."

Will Gardner, of charity ChildNet International, which advises parents and youngsters on how to use the net safely and was consulted on the Coronation Street storyline, says cases of older men and women using the net to "groom" young victims are still rare.

"But it is increasing," he says. "The first case in the UK went to court last October, and we've had six cases this year alone so far."

A teenage Internet chatroom is like a school playground, with lots of teens talking to each other, in groups or one-to-one, about whatever interests them - fashion, last night's football match or even homework.

The problem is, says Dr David Wall, director of the Centre for Criminal Justice Studies at Leeds University and an expert on cyber crime, that teenagers never really know who they are talking to when they're chatting online. Identities can easily be made up, he says. "There as a case of a 13-year-old girl who had been corresponding with a person who claimed to be a 13-year-old boy but who was in fact a 44-year-old man."

Actress Tina O'Brien, who plays Sarah Louise Platt, admits she herself has had one or two bad chatroom experiences - though nothing to compare with what her Corrie character goes through.

"Myself and a few mates were having a laugh and pretending to be someone called 'Gwendolin' - it was obviously a made-up name but people do that all the time," she says. This guy kept chatting to us and he was obviously getting very interested and he promised to send us a bunch of flowers. But then he started getting quite obscene and he was quickly cut off. I haven't really been in chatrooms since then."

So how can you be sure your teenage child isn't getting into deep waters? ChildNet International operates a website, ChatDanger.com, specifically to advise teenagers and parents on how to use the Internet safely.

Advice for teenagers:

- Never give out your name, address, passwords or school details - it's like giving out the keys to your home

- Don't meet anyone you contact through the web without getting your parents' permission first

- Remember that someone online may not be who they say they are

- Tell your teacher or parent if someone or something on the net makes you uncomfortable

Advice for parents:

- Keep the computer in a family room, not locked away in a child's bedroom

- Discuss the potential dangers with your children in a way that won't make them switch off. Checking out Childnet's www.Chatdanger.com website together may be a good way to start

- Don't allow your children to meet anyone they have contacted on the Internet unless you go with them

- If your child tells you they are being harassed by someone they think might be an adult, discuss this with them and contact the police immediately