A group of Twin Cities high school students is launching an advertising campaign designed to convince kids not to smoke. Students from Mounds Park Academy in St. Paul hope their message will get through to young people since it's coming from their peers. Minnesota Public Radio's Laura McCallum reports... A dozen or so students developed a poster in twelve different languages, a web site and a P-S-A for TV. In the video, children dressed in career clothes - a doctor, a construction worker, a dancer - are happily playing, until a pack of cigarettes crashes down in their midst... (nat - kids laughing, screech of cig pack, sound of heartbeat)