please help me i got the error con.open

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.Configuration;
using System.Data.SqlClient;

namespace login
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        SqlConnection con = new SqlConnection("data source=E:\\Jegan Works\\c sharp\\login\\login\\login.sdf;initial catalog=login;Integrated security=true");
        SqlCommand cmd;

        private void label1_Click(object sender, EventArgs e)
        {

        }

        private void button1_Click(object sender, EventArgs e)
        {
            cmd=new SqlCommand();
            cmd.Connection=con;
            cmd.CommandType=CommandType.Text ;
            cmd.CommandText="insert into login(username,password) values(@username,@password)";
            cmd.Parameters.AddWithValue("@username", username.Text);
            cmd.Parameters.AddWithValue("@password", password.Text);
            con.Open();
            cmd.ExecuteNonQuery();
            con.Close();
            MessageBox.Show("record inserted successfully");

        }
    }
}