Madison police have arrested two men after watching a situation unfold on surveillance cameras operating in the downtown area.  An officer monitoring the video shortly before 1:30 A-M Thursday saw a man get punched in the head and knocked unconscious.  Police say he had been going up to different people for a couple of hours trying to start a fight.  That’s why they were watching the video and that’s why 31-year-old Carlo Walkes was cited for disorderly conduct.  The man who knocked him out, 27-year-old Diorian Smith, faces a tentative charge of substantial battery.