cannot open sqlite connection it asking "Dbconnecton"

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Data.SQLite;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        SQLiteConnection cn = new SQLiteConnection(@"data source=C:\Sqlite\bbbb.db");
        private void button1_Click(object sender, EventArgs e)
        {
            SQLiteCommand cmd = new SQLiteCommand("select  name from personn ", cn);
            cn.Open();
            SQLiteDataReader dr = cmd.ExecuteReader();
            while (dr.Read())
            {
                string smd = (string)dr["name"].ToString();
                comboBox1.Items.Add(smd);
                
            }
            cn.Close();
        }

        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            SQLiteCommand cmd = new SQLiteCommand("select carnumb from personn where name ='" + comboBox1.Text + "' ", cn);
            cn.Open();
            SQLiteDataReader dr = cmd.ExecuteReader();
            while (dr.Read())
            {
                string smd = (string)dr["carnumb"].ToString();
                textBox1.Text = smd;
            }
            cn.Close();
        }
    }
}