AutoGenerate Id in asp.net

 
  int value = 12345;

        string alphabet = "0123456789ABCDEFGHJKLMNPQRSTUVWXYZ";

        var stack = new Stack<char>();

        while (value > 0)

        {

            stack.Push(alphabet[value % alphabet.Length]);

            value /= alphabet.Length;

        }

        string output = new string(stack.ToArray()).PadLeft(6, '0');

  private string GenerateId()
    {
        long i = 1, j = -1;

        foreach (byte b in Guid.NewGuid().ToByteArray()) { i *= ((int)b + 1); }

        foreach (byte b in Guid.NewGuid().ToByteArray()) { j *= ((int)b + 1); }

        var str1 = string.Format("{0:x}", (i - DateTime.Now.Millisecond));

        var str2 = string.Format("{0:x}", (j - DateTime.Now.Millisecond));

        return "EMC" + str1.Substring(0, 4) + str2.Substring(str2.Length / 2, 3);

    }