AutoComplete Text Box in wndows form

public partial class empassetReport : Form
   {
       AutoCompleteStringCollection namesCollection =new AutoCompleteStringCollection();
       public static bool isOpen = false;

       public empassetReport()
       {
           InitializeComponent();
       }

       private void empassetReport_Load(object sender, EventArgs e)
       {
           isOpen = true;

           this.Location = new Point(150, 100);
           SqlDataReader dReader;
           SqlConnection conn =Db.GetConnection();
           //conn.ConnectionString = strConnection;
           SqlCommand cmd = new SqlCommand();
           cmd.Connection = conn;
           cmd.CommandType = CommandType.Text;
           cmd.CommandText =
           "Select distinct(name) from empbirth" +
           " order by name asc";
           //conn.Open();
           dReader = cmd.ExecuteReader();
           if (dReader.HasRows == true)
           {
               while (dReader.Read())
                   namesCollection.Add(dReader["name"].ToString());

           }
           else
           {
               MessageBox.Show("Data not found");
           }
           dReader.Close();

           textBox1.AutoCompleteMode = AutoCompleteMode.Suggest;
           textBox1.AutoCompleteSource = AutoCompleteSource.CustomSource;
           textBox1.AutoCompleteCustomSource = namesCollection;


       }