SQL & PL/SQL

Hi

is there some way for a query to order ASC or DESC when the user to pass 1 or 2 in parameter
EXPLAIN

   Select  column1,column2...column3
      from  mytables
       WHERE .....
      ORDER BY   -- here I must put ASC  if user put 1 in Parameter in Procedure or  DESC
        if user put 2

tia