Make Me A Virgin (C4, 11.10pm), The Good Samaritan (ITV, 9pm), Natural World: The Bloodhound And The Beardie (BBC, 9pm)

THE end credits of Make Me A Virgin contain the most unusual thank you I've seen on a TV programme. The list of names of those who've helped the film-makers concludes with "Thanks to... whoever gave Jamie clamydia".

Why film-maker Jamie Campbell felt obliged to include a reference to his own sexually transmitted disease in his documentary on sexual abstinence must wait as The Good Samaritan is passing by.

This comedy drama opened with a man teetering on the edge of the roof of a tower block contemplating suicide. After half an hour of Peter Whalley's film, you may feel like joining him. Not even the presence of the aimiable, affable, likeable (and any other -ables you'd care to name) Shane Richie can keep this afloat.

He's Brian Guest, whom the potential suicide rings under the mistaken impression he's calling The Samaritans. Brian advises him to jump because he thinks the call is from a friend winding him up, although you wonder what sort of friend plays a sick joke like that.When Brian discovers he's pushed someone over the edge, he determines to make amends to the supposedly dead man's family. "I'm going to make up for this terrible thing I have done," he says.

I'm not sure there's anything Richie can do to compensate for The Good Samaritan, but Holly and Herbie show you can teach an old dog new tricks.

Bloodhound Holly and bearded collie Herbie are both rescue dogs being given the chance of a new life. They have chequered pasts. Destructive Holly has had six homes in ten months. Herbie has been labelled a "serial sheep chaser".

Natural World follows the two wayward canines - Holly in West Virginia, Herbie in Yorkshire - as they train for their new lives. The aah factor is high as they turn over new leaves. "Look how close he's going without eating them," says trainer Barbara as Herbie manages to round up sheep without biting them.

Holly shows equal discipline by sniffing out one man in a crowd of 2,000 people as she's trained to work for the Massachusetts State Police.

"He's well-mannered and he's reasonably obedient," says Barbara at the end, making Herbie sound like a well-trained husband.

And so back to Jamie and the clap in Make Me A Virgin. Describing himself as an ex-evangelical Christian, the film-maker's hired to make a promotional film for The Silver Ring Thing. This isn't a spin-off from The Lord Of The Rings but a US organisation preaching sexual abstinence and out to recruit over here.

What he discovered - apart from having clamydia after someone he interviewed suggested he take a test - was "a cocktail of religious fundamentalism, misinformation and sexual confusion".

Along the way he learnt several techniques for remaining pure. The "bouncing eyes" method is simple, just avert your eyes when confronted by potentially stimulating images such as bouncy breasts or pert bottoms.

Away from home, you should scatter pictures of your family around the hotel room and demand that the management disconnect the porn channel in your room.

At rallies, the danger of having sex before marriage is illustrated by a man on stage using a chainsaw to cut a large wooden heart in half. How different to sex education lessons in our schools where teachers demonstrate putting on a condom and discuss threesomes. Does bouncing your eyes away while you're doing it count as abstinence, I wonder?

Campbell discovers the link between faith and abstinence is great, and that keeping people pure is big business. Quite apart from the $15 teenagers pay for silver rings, there's the $1m the organisation has received from the Bush administration.

Campbell interviews one couple, Jasen and Rose, who saved themselves for marriage, and seem happy and normal. He didn't even kiss Rose before their wedding day. He also didn't masturbate, although she did. He's forgiven her.

"Will you teach your children to do the same thing?" asks Campbell.

"What, masturbate?" asks Rose.