Quering records in Access

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Data.OleDb; //make sure u add this namespace

namespace WindowsApplication3
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
           
            OleDbConnection con = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=D:\Database1.mdb;Persist Security Info=False");
            con.Open();
            string query = "Select name1 from mytable where id='"+comboBox1.Text+"'";
            OleDbCommand cmd = new OleDbCommand(query,con);
            OleDbDataReader dr = cmd.ExecuteReader();
            if(dr.Read()==true)
            {
                textBox1.Text = dr[0].ToString();
            }
            else
            {
                MessageBox.Show("No such record");
            }
            con.Close();
            con.Dispose();

        }

        private void Form1_Load(object sender, EventArgs e)
        {
            comboBox1.Items.Clear();
            OleDbConnection con = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=D:\Database1.mdb;Persist Security Info=False");
            con.Open();
            string query = "select id from mytable";
            OleDbCommand cmd = new OleDbCommand(query, con);
            OleDbDataReader dr = cmd.ExecuteReader();
            while (dr.Read() == true)
            {
                comboBox1.Items.Add(dr[0].ToString());
            }
            con.Close();
            con.Dispose();

        }
    }
}