/// <summary>
/// method to generate a MD5 hash of a string
/// </summary>
/// <param name="strToHash">string to hash</param>
/// <returns>hashed string</returns>
public string GenerateMD5(string str)
{
  MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();
  byte[] byteArray = Encoding.ASCII.GetBytes(str);
  byteArray = md5.ComputeHash(byteArray);
  string hashedValue = "";
  foreach (byte b in byteArray)
  {
    hashedValue += b.ToString("x2");
  }
  return hashedValue;
}