The FRONTLINE special, "Dropout Nation," airs tonight at 8 p.m. Central on SDPB-TV. Every year, hundreds of thousands of teenagers in the United States quit high school without diplomas. FRONTLINE spent a semester immersed in Sharpstown High School in Houston, once a notorious "dropout factory," to produce a portrait of four students in crisis and the teachers, counselors and principal waging a daily struggle to get them to graduate. Dakota Midday host Karl Gehrke is joined by FRONTLINE producer Frank Koughan.