Level  Code
-----------------------
  1     Starting game
  2     555-4239
  3     555-6767
  4     555-8942
  5     555-4118
  6     555-8471
  7     555-2989
  8     555-6737
  9     555-6429
 10     555-1881

Codewords by Doctor D - docd@beer.com