TEENAGERS will be given an opportunity to produce educational cassettes and slides promoting the anti-drug message in a youth broadcast competition. The joint programme of the Boys' and Girls' Clubs Association, RTHK Radio 2 and the Action Committee Against Narcotics, now in its second year, requires participants to produce a five-minute cassette or slide presentation on the subject. The winning entries will be recorded and broadcast on RTHK in a bid to spread the message to the public. ''This year we chose drug abuse as our theme because of the increasing number of youths who are beginning to use drugs at an earlier age. ''We hope the contest can spread the anti-drug message and provide teenagers a chance to share their feelings on the topic,'' said Mr Kwong Kam-fai, spokesman for the Boys' and Girls' Clubs Association. Statistics by the Central Registry of Drug Abuse show the age of drug addicts is dropping. Of the over 2,900 newly reported addicts last year, 52 per cent began abusing drugs before they reached the age of 20. This compared with about 43 per cent of the 2,697 newly reported drug abusers in 1991. ''Besides, the participants will learn more about the basic techniques of cassette and slide production. This will be interesting and educational.'' There will be three topics for the competition; these are ''The Temptation of Pills'', ''The Inner Feelings of Teenagers'', and ''The Joy and Sadness in Life''. Participating teams, with two to five people in a group, can submit their entries in cassettes or together with slides. They can use whatever approaches they like such as drama, discussion or interviews to express their ideas. The judging panel will include Lingnan College lecturer Dr Sze Man-hung, Mrs Justina Leung of the Boys' and Girls' Clubs Association, Mr Leung Siu-fai of RTHK Radio 2, and representatives from the Government's Narcotics Division. Entries will be judged on creativity (40 per cent), content (40 per cent) and technique of expression (20 per cent). The winner will receive a trophy and a cash award of $1,500. The first and second runners-up will be awarded $1,000 and $500, respectively. The prize presentation will be held on January 29. Winning entries will be broadcast on RTHK Radio 2 and at shopping malls. Young people aged between 14 and 25 are welcome. The deadline for applications is October 31. The heats will be held in November and the final in January. For more information, call the association on 850-7237 or 729-2294.