How no is the Scottish vernacular of "Why Not".  Mostly used along Scotland's western shires it could be a question or a confirmation.  I swore I would not run ultra marathons, particularly the off road mountain ultras, until I supported Steven on his West Highland Way Race attempt in 2013.  After many years of refusing to get caught up in this crazy sport Steven posed the question to me again.  "Why don't you enter an ultra?".  I said "How no!" :)