CREATE TRIGGER ntdel AFTER UPDATE ON nodetext
	FOR EACH ROW
	BEGIN
		IF NEW.is_deleted = 1 THEN
			BEGIN
				IF (SELECT COUNT(*) FROM nodetext WHERE is_deleted=0 AND textbox_id=NEW.textbox_id) = 1 THEN
					UPDATE textboxes SET is_deleted=1, modified_date=NOW() WHERE textbox_id=NEW.textbox_id;
				END IF;
			END;
		END IF;
	END;
//

A known working trigger follows:


CREATE TRIGGER conndel AFTER UPDATE ON connections
	FOR EACH ROW
	BEGIN
		IF NEW.is_deleted = 1 THEN
			UPDATE sourcenodes SET is_deleted=1, modified_date=NOW() WHERE connection_id=NEW.connection_id;
		END IF;
	END;
//