Texbox autocompletion

Question

Hi Sirs!

 

I am trying to make my textbox "autocompletion".

When I run my codes its giving this message:

The name 'ConfigurationManager' does not exist in the current context 

 

 Please have a look to my codes:

 

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Configuration;

using System.Data.SqlClient;

using System.Windows.Forms;

namespace AutoCompleteTextBox

{

public partial class frmAuto : Form

{

public string strConnection = ConfigurationManager.AppSettings["ConnString"]; // Its here the bug

AutoCompleteStringCollection namesCollection = new AutoCompleteStringCollection();

public frmAuto()

{

InitializeComponent();

}

private void frmAuto_Load(object sender, EventArgs e)

{

SqlDataReader dReader;

SqlConnection conn = new SqlConnection();

conn.ConnectionString = strConnection;

SqlCommand cmd = new SqlCommand();

cmd.Connection = conn;

cmd.CommandType = CommandType.Text;

cmd.CommandText = "Select distinct [Name] from [Names] 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();

txtName.AutoCompleteMode = AutoCompleteMode.Suggest;

txtName.AutoCompleteSource = AutoCompleteSource.CustomSource;

txtName.AutoCompleteCustomSource = namesCollection;

}

private void btnCancel_Click(object sender, EventArgs e)

{

Application.Exit();

}

private void btnOk_Click(object sender, EventArgs e)

{

MessageBox.Show("Ñice practice");

}

}

}