MITCHELL, S.D. (MITCHELLNOW) One South Dakota high school plans to give students breathalyzer tests at prom this year.  Madison High School has decided to take this new approach as part of extra efforts to keep students safe. Principal Adam Shaw says the breath test was an idea that will reduce the chances of drinking throughout the night.  It was approved by the School Board and able to be done with a continued partnership with Madison Police.  According to officials, the tests will be quick, non-invasive and private.  Shaw says more schools are starting to get on board with using breathalyzers at prom.