private void bGo_Click(object sender, EventArgs e)
        {
            try
              {
            //Make sure that we have a value
            if (string.IsNullOrWhiteSpace(tSourceString.Text))
              throw new ApplicationException("No source string provided.");

            Rijndael rijndael = new Rijndael(_key, _iv);

            string input = tSourceString.Text.Trim();

            string output;
            if (rbEncrypt.Checked)
            {
              output = rijndael.Encrypt(input);
            }
            else
            {
              output = rijndael.Decrypt(tSourceString.Text);
            }

            tOutputString.Text = output;
              }
              catch (Exception ex)
              {
            DisplayError(ex.Message);
              }
        }
        private void AssignConnectionString()
        {
            //Attempt to retrieve the connection string from the web.config file
              ConnectionStringSettings connStrSettings;
              if ((connStrSettings = ConfigurationManager.ConnectionStrings["MsSqlRepository"]) == null)
            throw new ConnectionStringAssignmentException();

              //We expect the connection string to be encrypted, so decrypt it
              string encryptedConnStr = connStrSettings.ConnectionString;

              Rijndael rijndael = new Rijndael(_key, _iv);
              _connectionString = rijndael.Decrypt(encryptedConnStr);
        }