SQL command for value comparison

Hi,

I would like to compare 2 attributes before display the result using SQL command

     e.g  new_due_date   old_due_date    result to display
     -----------------------------------------------------------
          11 Feb 2001         15 Feb 2001     in
          12 Feb 2001         08 Feb 2001     out


"select decode((new_due_date<old_due_date),'in','out') from XYZ"  will not be
working as decode only compare exact value.

Please help and thanks in advance.

Regards,
Patricia