"Positivity" is a word Kadin likes to use. "My purpose in life is to spread positivity in a negative world," he wrote recently. Kadin uses writing and music as tools to build that world. I Kadin through his writing. He writes just about every day, and he always has something important to say--about drug use, violence, responsibility, and doing the right thing. Today it's your turn to meet 16-year-old Kadin McElwain.