Help with sudoku

[Donanza]

Hi guys!
I was helped by a member in this forum with the sudoku, but i got
stuck trying to add some code.
I want to add a warning if the number the user adds in is in the row
or is in the column.
So far i made the code, but is wrong:

for(int i = 0; i < 9; i++){
          if(sudokuplayer[row][i] != sudoku1[row][i]) cout << "\n Warning! This number is in the row";
          if(sudokuplayer[i][column] != sudoku1[i][column]) cout << "\n Warning! This number is in the column ";
          }

Pls help me!