The Puzzle:

 Smith, Robinson and Jones are fireman, brakesman and engine-driver of a train,
 but NOT in this succession. On the same train are three businessmen with the
 same names: Mr.Smith, Mr.Robinson and Mr.Jones.

 1. Mr.Robinson lives in Detroit.
 2. The brakesman lives exactly in the middle between Chicago and Detroit.
 3. Mr.Jones earns 20.000 Dollar per year.
 4. The nearest neighbour of the breakesman is one of the businessmen, and he
    earns exactly three times as much as the breakesman.
 5. Smith beates the fireman in the billiards game.
 6. The businessman who has the same name as the brakesman, lives in Chicago.

 What is the name of the engine-driver?



 Hints: This is no kind of joke!
        EVERY 6 points are important!