calculate someone's age in C#?

 int now = int.Parse(DateTime.Today.ToString("yyyyMMdd"));
 int dob = int.Parse(dateDOB.ToString("yyyyMMdd"));
 string dif = (now - dob).ToString();
 string age = "0";
 if (dif.Length > 4)
     age = dif.Substring(0, dif.Length - 4);