Filter Combo box or make combo box searchable

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.OleDb;
namespace Filter_Combobox
{
    public partial class Form1 : Form
    {
        string ConnectionString = System.Configuration.ConfigurationSettings.AppSettings["dsn"];
        OleDbCommand com;
        OleDbDataAdapter oda;
        DataSet ds;
        string str;

        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            bind();
        }
        private void bind()
        {
            comboBox1.Text = "--Select--";
            OleDbConnection con = new OleDbConnection(ConnectionString);
            con.Open();
            str = "select * from prod ";
            com = new OleDbCommand(str, con);
            oda = new OleDbDataAdapter(com);
            ds = new DataSet();
            oda.Fill(ds, "prod");
            comboBox1.Items.Clear();
            comboBox1.DataSource = ds.Tables["prod"];
            comboBox1.ValueMember = "Modelid";
            comboBox1.DisplayMember = "ModelNo";
            con.Close();
        }

        private void comboBox1_MouseDown(object sender, MouseEventArgs e)
        {
            OleDbConnection con = new OleDbConnection(ConnectionString);
            con.Open();
            str = "select * from prod where ModelNo like '%" + comboBox1.Text + "%'";
            com = new OleDbCommand(str, con);
            oda = new OleDbDataAdapter(com);
            ds = new DataSet();
            oda.Fill(ds, "prod");
            comboBox1.DataSource = ds.Tables["prod"];
            comboBox1.ValueMember = "Modelid";
            comboBox1.DisplayMember = "ModelNo";
            con.Close();
            comboBox1.Text = "";
        }
    }
}


Thanks
If this post helps you mark it as answer