[RESOLVED] DB (Access or SQL Server) - Using pure SQL find first available Key in Table

[jcis]

How to get the first Key available in a given Table, assumming some entries has been deleted, there are gaps, i need an SQL Query to get the first available, examples:

1, 2, 3, 6, 7, 8, 10, 14, 15
(it should return 4)

6, 7, 8, 10, 14, 15
(it should return 1)

I did this one, but there is a problem, this query returns the Key available after the first gap, not before..

      SELECT MIN(a.CODE-1)
        FROM Table AS a 
  LEFT JOIN Table AS b ON a.CODE - 1 =  b.CODE
      WHERE b.CODE IS NULL AND a.CODE <> 1;