protected void radioListManufacturers_SelectedIndexChanged(object sender, EventArgs e)
    {
        
        //get the manufacturer that the user selected
        string manufSelect = radioListManufacturers.SelectedValue.ToString();
        Label1.Text = manufSelect;

        //Run a SELECT statement to get all the model names,
        //that match the manufacturer selected

        MySqlConnection conn = new MySqlConnection(DataAccessClass.GetConnectionString("AFPConnection"));
        
        MySqlCommand com = conn.CreateCommand();
        
        com.CommandType = CommandType.Text;
        com.CommandText = "SELECT DISTINCT modelname FROM basevehicle WHERE(manufacturer = ?vManu)";
        com.Parameters.Add
("?vManu", MySqlDbType.VarChar).Value = manufSelect;
        
        //create dataset
        DataSet dsModels = new DataSet();

        //dataAdapter
        MySqlDataAdapter adapter = new MySqlDataAdapter();
        adapter.SelectCommand = com;
        
        //fill dataset
        adapter.Fill(dsModels);

        //tell radiobuttonlist where the info is and bind it
        radioListModels.DataSource = dsModels;
        radioListModels.DataBind();

        //tell the gridview where the info is and bind it
        GridView1.DataSource = dsModels;
        GridView1.DataBind();
      }

modelname
--------------
Rodeo

      //fill dataset and give it the name of the table
        adapter.Fill(dsModels,"modelname");

      //tell radiobuttonlist where the info is and bind it
        radioListModels.DataSource = dsModels.Tables[0];
        
       //tell it where to get the text field you want
        radioListModels.DataTextField = "modelname";
        radioListModels.DataValueField = "modelname";

        radioListModels.DataBind();