function difference list1,list2
  toComputer
  put empty into theList
  repeat with x = 1 to the number of lines of list1
    if line x of list1 is not in list2 then
      put the number of lines of theList + 1 into lastLine
      put line x of list1 into line lastLine of theList
    end if
  end repeat
  repeat with x = 1 to the number of lines of list2
    if line x of list2 is not in list1 then
      put the number of lines of theList + 1 into lastLine
      put line x of list2 into line lastLine of theList
    end if
  end repeat
  sort theList
  return theList
end difference