MASON Gamble is a seven-year-old caught somewhere between being ''just a kid'', as he describes himself, and the serious demands of adulthood. A few months after being signed up by his father's agent in Chicago, the then six-year-old Mason scored the leading role in Warner Bros' family comedy, Dennis The Menace - due in Hongkong in mid August - starring alongside such luminaries as Walter Matthau and Joan Plowright. His was among 20,000 submitted video auditions - or as Mason says: ''20,000 and one!''. This number was pared down to 100 possibles before 10 finalists were screen tested with Walter Matthau for the part. The film-makers were looking for a child of about six who had a good personality, discipline and a good sense of humour to bring the 50s comic strip character to life for the big screen. It was young Mason who filled the bill. While Mason would much prefer playing with bugs, his new career means he has to sit still and answer the questions of reporters, talk on radio and appear on chat shows. During one extraordinarily demanding part of his schedule when the film was released in America, Mason was put through 120 interviews over two days in Los Angeles. This was just before he began his Asian tour - last Friday he attended the premiere in Chicago, where the movie was filmed, the following day he attended the Dennis the Menace premier in Los Angeles, caught the red eye back to Chicago for a charity benefit on Sunday and flew out for Taiwan on Monday. As producer and writer John Hughes said: ''It's a big job for a little kid''. At 10am yesterday Mason was already munching on his third meal of the day - hotdog and french fries - at Hongkong's Conrad Hotel. Again he was in the hot seat in a promotional tour that has already taken him to Taipei and Tokyo and leads to five European cities before he heads home at the end of the month. When I asked Mason if being an actor was hard work, Mason described it as ''hot work''. Making Dennis The Menace was ''very fun'', acting is fun because he ''gets to meet other people'' doing interviews is ''kind of boring''. His favourite actor is Arnold Schwarzenegger - he likes adventure movies. But when it came to talking about being a little boy earning a big salary, a determined young man came to the fore. ''I not going to talk about that . . . I don't have to answer that,'' said seriously cute Mason, sitting back in his poolside chair. When I asked his father, Tim, how much money Mason had earned for his months of eight-hour days on the set, Mason piped up: ''Don't tell her!''. ''It is important to us that money doesn't disguise whether Mason really enjoys doing this,'' replied Tim Mason. Mason's father has been earning a comfortable living appearing in television commercials and getting small parts in films for the past 12 years. Mum, Sally, is a trained developmental psychologist who now sells nutrition supplements and products. All three professions have played a part in the shaping of Mason Gamble. ''We did not want our children in this business,'' stated father Tim. ''We want to raise good parents ourselves - very evidently this business does not lend itself to that. ''But we can say with a clear conscience that the Lord has obviously stepped in,'' said Tim Gamble. ''I figured after three weeks on that set he'd get sick of it. Sometimes he would have to anything from 25 to 40 takes for special effects shots, but he'd just do it and do it. I don't know many adult actors who would do that. ''This child has an appetite for hard work.'' When I asked him if as parents they were concerned about raising Mason as a normal kid, Tim laughed, ''I'd like someone to tell me what that is. First of all, this could be the end of it - that very much depends on Mason.'' So, does he want to continue acting? ''Yes, I do''. ''Why in the world would you want to do that?'' asked his father. ''Because it's fun,'' came the simple reply. Mason's school friends have mostly got over his leap to fame since he returned from the set to begin first grade. ''Some that were friends before now treat me like a king; not my best friends, they still treat me like a friend,'' said Mason. Director Nick Castle praised young Mason as one of the smartest actors he had ever worked with - ''he has amazingly strong instincts for drama and comedy both. In terms of comic timing and abilities, he's absolutely, totally amazing for his age.'' On screen Mason does look like he's having fun, that he enjoys being a six-year-old rascal who just can't help getting himself and others around him into trouble. Perhaps mindful of child star Macauley Culkin, whose leap to mega stardom was created by producer John Hughes with Home Alone, Mason has stopped wanting to be a movie star. When asked by his father whether he'd like to be a star or an actor, Mason replies with a serious look, ''an actor''.
