Auto-Complete in textbox using data from a SQL Server database in -- Windows Forms Application c#

Auto-Complete in textbox using data from a SQL Server database:

I am trying to get my textbox to auto-complete when a user types in it to write a query. This would be similar to how SQL Server Management Studio does it and gives the option as you type to arrow down or click on a table name or column name. Here is the following code I have.......

C#(Code).....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.SqlClient;

namespace Auto_complet_textbox_shown_data

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        private void autoCompleteData() 

          

                    { 

                        SqlConnection con = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=c:\users\surendrak\documents\visual studio 2010\Projects\Auto complet textbox shown data\Auto complet textbox shown data\Database1.mdf;Integrated Security=True;User Instance=True"); 

                        SqlCommand com = new SqlCommand("Select State from tbl_State", con); 

                        con.Open(); 

                        SqlDataReader rdr = com.ExecuteReader(); 

                        //AutoCompleteStringCollection Contains a collection of strings to use for the auto-complete feature on certain Windows Forms controls. 

                        AutoCompleteStringCollection autoCompleteCollection = new AutoCompleteStringCollection(); 

                        while (rdr.Read()) 

                        { 

                            autoCompleteCollection.Add(rdr.GetString(0)); 

                        } 

                        //Set AutoCompleteSource property of txt_StateName as CustomSource 

                        txt_StateName.AutoCompleteSource = AutoCompleteSource.CustomSource; 

                        //Set AutoCompleteMode property of txt_StateName as SuggestAppend. SuggestAppend Applies both Suggest and Append 

                        txt_StateName.AutoCompleteMode = AutoCompleteMode.SuggestAppend; 

                        txt_StateName.AutoCompleteCustomSource = autoCompleteCollection; 

                        con.Close(); 

                    } 

        private void Form1_Load(object sender, EventArgs e)

        {

           autoCompleteData(); 

        }

    }

}

(And i can use sql database in this application)

using System.Data.SqlClient;