How do you get promoted I have been a Major for over a year and my son has bee a private. What do you have to do to get promoted>

Your Rank is based on your "Championship Point" standings.

http://www.wargear.net/wiki/doku.php?id=achievements

Championship points are gained by becoming one of the top 10 players on any board. 

http://www.wargear.net/wiki/doku.php?id=general:help:rankings#board_rankings_and_championship_points

So you have earned your current rank in large part due to your #3 ranking on the "Clue" board.