FOURTH-former Ah Ming (not his real name) said life in school has become a ''fierce battle'' with the discipline master. Tension is great as he and his classmates steel themselves for ''very harsh and insulting penalties'' for the slightest infringement of rules. Ah Ming said there was a time when a teacher would paint ''humiliating'' words on the face and arms of any student caught being rude to the others. The student then had to walk from class to class in disgrace. Once a student found smoking in the toilet was made to ''stick a cigarette in his mouth during recess and go around telling the others 'I will never smoke again' ''. Ah Ming said students had reported the case to the principal, who told them that ''everyteacher had his own way of dealing with problems.'' Ah Ming said the only person he can turn to in times of difficulty is the social worker, who in turn tells him to speak to his parents. But he feels this would be fruitless as the school never approaches his parents about any matter.