var alpha = new string[]{"a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z"};
var currFilename = "";
var suffix = ""; //this will become a or ef or whatever we work out
for (var i = -26; i<676; i++)
{
  if(i < 0)
  //convert the negative to positive.
  //Need to subract from 26 to correct the order ie 0-26 rather than 26-0
  //which alphabetically reverses the single letter suffixes
    suffix = alpha[26 - (i * -1)];
  else
    suffix = alpha[i / 26] + alpha[i % 26];
  currFilename = string.Format("{0}{1}.wav", this.Author.WinscribeAuthorID, suffix);
}