ADO Database C#

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using System.Data.SqlClient;
public class Form1 : System.Windows.Forms.Form {
    const string strConnect = "data source=\".\";database='biblio';uid=\"admin\";pwd=pw";
    string strQuery = "Select Title, Price from Titles where Title like 'Hit%'";
    SqlConnection cn = new SqlConnection(strConnect); // = new SqlDataAdapter();
    DataSet ds = new DataSet();
    internal System.Windows.Forms.Button Button1;
    internal System.Windows.Forms.DataGrid DataGrid1;
    private System.Data.SqlClient.SqlDataAdapter da;
    public Form1() {
        this.Button1 = new System.Windows.Forms.Button();
        this.DataGrid1 = new System.Windows.Forms.DataGrid();
        this.da = new System.Data.SqlClient.SqlDataAdapter();
        ((System.ComponentModel.ISupportInitialize)(this.DataGrid1)).BeginInit();
        this.SuspendLayout();
        this.Button1.Location = new System.Drawing.Point(168, 266);
        this.Button1.Size = new System.Drawing.Size(96, 32);
        this.Button1.Text = "Get Data";
        this.Button1.Click += new System.EventHandler(this.Button1_Click);
        this.DataGrid1.DataMember = "";
        this.DataGrid1.HeaderForeColor = System.Drawing.SystemColors.ControlText;
        this.DataGrid1.Location = new System.Drawing.Point(8, 18);
        this.DataGrid1.Size = new System.Drawing.Size(392, 232);
        this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
        this.ClientSize = new System.Drawing.Size(408, 317);
        this.Controls.AddRange(new System.Windows.Forms.Control[] {
                                                                          this.Button1,
                                                                          this.DataGrid1});
        this.Load += new System.EventHandler(this.Form1_Load);
        ((System.ComponentModel.ISupportInitialize)(this.DataGrid1)).EndInit();
        this.ResumeLayout(false);
    }
    [STAThread]
    static void Main() {
        Application.Run(new Form1());
    }
    private void Form1_Load(object sender, System.EventArgs e) {
        try {
            cn.Open();
            da.SelectCommand = new SqlCommand(strQuery, cn);
        } catch (SqlException ex) {
            Console.WriteLine(ex.ToString());
        }
    }
    private void Button1_Click(object sender, System.EventArgs e) {
        da.Fill(ds, "Titles and Price");
        DataGrid1.DataSource = ds.Tables["Titles and Price"];
    }
}