I've been trying to come up with an efficient function which will create a series of strings, each of which contains the numbers 0 - 9 in all possible permutations. The only proviso is that no number must be repeated in the string - every digit must be unique. DIM 10 String$(3628800) String$(n) = "0123456789" The function I've written is incredibly verbose and clunky, and I wondered if any of you mathematicians could come up with a small, efficient one. Phil