updating a field... in SQL DB...plz HELP

[phoenix911]

hey guys/girls

i do need some help with my application(console)

at the moment, im reading from my SQL DB, into classes for each table...(or to the respective classes)

anyway...

i cant seem to get the update part right, for instance i'd like to change someones surname...

public static DataSet ReadClientData(string id)
        {
            SqlDataAdapter adapter = new SqlDataAdapter();
            DataSet dataset = new DataSet("client");
            adapter.SelectCommand = new SqlCommand(GetStandardQueryString("client", id));
            SqlConnection connection = new SqlConnection(connectionString);
            adapter.SelectCommand.Connection = connection;
            adapter.Fill(dataset, "client");
            connection.Close();
            return dataset;
        }

thats my read... i dont have my write, as i deleted it after struggling for hours...

thanx