A policeman pulls a driver over for swerving in and out of lanes on the highway. He tells the guy to blow into a breathalyzer."I can't do that, officer, I'm an asthmatic. I could get an asthma attack if I blow into that tube.""OK, we'll just get a urine sample down at the station.""Can't do that either, officer. I'm a diabetic. I could get low blood sugar if I pee in a cup.""Alright, we could get a blood sample.""Can't do that either, officer. I'm a hemophiliac. If I give blood, I could die.""Fine then, just walk this white line.""Can't do that either, officer.""Why not?""Because I'm drunk."