Helen Gurley Brown, author of the best-selling Sex and the Single Girl, is in England to start a war. Her target: the newly emancipated, trendy world of a handful of British women's glossy magazines. Her ammunition: a saucy, man-catching magazine called Cosmopolitan. On the home front, faced with big circulation problems, her rivals nervously maintain there's no room for another glossy. And, not surprisingly, the prospect of a British version of Cosmopolitan is causing quite a stir. Some people are afraid of Helen Gurley Brown. Her big guns are being aimed at glossies like Nova and 19, magazines which have done away with the 'worried blue-eyes' image and now frankly discuss things like virginity and VD. Others remain unmoved, like Mrs Betty Kenward, otherwise 'Jennifer' of Harpers Queen. Her diary, and her values, will definitely not change. Even Helen Gurley Brown can't alter that.