Brainteaser: Sudoku Puzzle

Copy this grid down.  Then fill in the empty boxes such that:

There is one correct answer, and it can be solved logically without guessing

Hints for solving a sudoku puzzle            Click here for the answer

  3   1   8 5    
4   5   2 9   6 8
  1              
1 8       7      
                 
      5       4 9
              8  
2 6   7 4   9   3
    3 2   1   7