'It's a popular joke in editorial that if you took 100 people off the street and said, 'who could write a Mills & Boon?' At least 85 would put their hands up and maybe one of them could,' she says.

Even then, it's a big maybe. Anyone with the necessary talent - yes, talent, for Mills & Boon editors can smell formula writing a mile away, Laing says - must follow strict guidelines covering not just the obvious such as how much, if any, sex, but the main characters' ages and nationalities, suitable settings, even the way in which the characters are described.

All the main imprints, Mills & Boon, Harlequin, Silhouette, for instance, issue such guidelines and it's usually pointless to begin writing without them. Mills & Boon even has a 40-minute audio tape which those who receive the guidelines can mail order to point them even more firmly in the right direction.

It's called And Then He Kissed Her, and if that sound sickening to you, cross yourself off the list of potential romance writers.

'If you are not a reader, you are not going to be able to write Mills & Boon,' Laing says. 'This week I have just been reading some of my unsolicited manuscripts and I would say a good 25 per cent have never picked up and read a Mills & Boon in their lives but they think they can do it anyway.' Mills & Boon's guidelines sum up its plots as dealing with a love that is resolved happily: 'The emphasis is on the shattering power of that love to change lives, to develop character, to transform perception. It should be treated as a once-in-a-lifetime happening.' While Laing concedes it's possible for a talented writer to learn the rules, she believes to create that extra something that attracts an editor's attention, the writer must be a romantic: 'We are all pretty slushy at heart in the office,' she says. 'Yes, I think you have got to believe in it.' Valerie Parv agrees: 'You could possibly fake it for a while, but I don't know if you could keep it up,' she says. Parv, an Australian former journalist and non-fiction writer who decided there must be an easier way to earn a living than do-it-yourself plumbing books, has published 31 books for Mills & Boon since her first in 1982.

'I've been married 23 years and I'm still a starry-eyed romantic. My husband and I spring surprises, give each other presents. It took us a while to realise not everybody does that.

'And I had the foresight to marry an archetypal Mills & Boon hero. My husband Paul was a crocodile and buffalo hunter before I knew him.' Parv's work has been translated into 22 languages and she has sold more than 10 million books, making her a wealthy woman; though she refuses to say just how wealthy or to reveal her royalties. Laing says Mills & Boon pays less than 10 per cent, but romance imprints are generally regarded as low paying, with the chance to make big money because of the size of the market.

Mills & Boon, which alone has about 200 active authors and publishes 600 new titles a year, says seven out of 10 women reading fiction at any time will be reading a romance.

Harlequin, the Mills & Boon parent company, says more than 200 million women a year read its books, with North America its biggest market. Half are aged 25 to 34 and - contrary to suggestions that such books are the choice of bored housewives - they comprise only a third of all readers.

Parv says romances account for almost half the paperbacks sold in the world. The potential for such sales and the apparent simplicity of the books inevitably attracts large numbers of would-be authors. That has created a whole new market - the how-to market.

Parv is a leading member: she has converted a home study course she offered would-be writers into a book, The Art of Romance Writing. In it she deals with each component of a romantic novel, offers practical pointers from presentation of a manuscript (leave 3cm margins, don't bind or staple, use rubber bands, don't use a dot matrix printer) to addresses of publishers and organisations such as romance writers associations and newsletters such as Romantic Times.

One glance at Parv's 140-page book is enough to persuade that this is a form of writing that takes careful research and planning as much as skill and adherence to guidelines. Take Parv's chapter on characterisation: several pages are devoted to the choice of names, and factors such as whether the heroine's name sounds attractive when she marries the hero and changes her name must be considered.

In the chapter on viewpoint, Parv explains how to tell a story from one character's viewpoint and how to switch viewpoints. Using the heroine's viewpoint involves describing the world through her eyes - herself included. That means using devices such as her reflection in a mirror or shop window.

Parv not only reads several new romances a month to keep up with the trends, she reads widely, constantly looking for new ideas. In an agricultural journal, for instance, she found an interview with a farm secretary to whom she wrote for more information about her job, using it for her heroine in Man Shy.

Parv began by writing three chapters of her first novel and an outline of the rest - an approach favoured by Mills & Boon, though imprints' requirements vary. She now averages three books a year, thinking through her ideas in the garden of her Sydney home, then writing on a word processor. She is so commonly asked where her ideas come from she is writing a book about that too, The Idea Factory, to be published next year.

'I feel that technique is something you can learn, but the inspiration comes from the individual,' she says.

Even then, it's important to find the imprint that's right for you. To write for Harlequin Intrigue, it's necessary to blend suspense and mystery with the romance for 70,000 to 75,000 words. While Silhouette Romance titles (53,000 to 58,000 words) don't have the hero and heroine make love unless they are married, Silhouette Desire guidelines says: 'The characters don't have to be married to make love, but love-making is never taken lightly.' Silhouette Intimate Moments (80,000 to 85,000 words) 'combine the universally appealing elements of a category romance with the flash and excitement of mainstream fiction'.

Parv herself has only once written for another imprint: 'The book went to Mills & Boon, it went through editorial and it was only as it went to the acquisitions committee that they decided maybe England wasn't ready for a Mills & Boon with a UFO in it.' The book was published by US-based Silhouette.

Parv says people are less scathing than they used to be when they learn about her work and romance writers are coming 'out of the closet', doing book signings and speaking at writers' festivals.

Laing, who reads books from all the Harlequin lines in her spare time but says there's nothing like Jane Austen if you're depressed and it's cold, says the themes in movies are reflected in the mass books market. A passion for US ranch stories and Australian outback settings have recently been big.

'If you asked most people what they thought of Mills & Boon, they would go 'blah', but it is remarkable how discriminating the readers are.' Potential writers are also waking up to the realities of this massive market too: 'I think people now realise that it is a very tough business,' Laing says.