In celldouble click event string format is not correct. error is generated..

Revision 1
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 ass3cs
{
public partial class show_database : Form
{
public show_database()
{
InitializeComponent();
}

private void show_database_Load(object sender, EventArgs e)
{
SqlConnection dbconnection = new SqlConnection("Data Source=.\\SQLEXPRESS;AttachDbFilename=E:\\edu\\7th sem\\a.net\\assignment\\ass3cs\\ass3cs\\BikeData.mdf;Integrated Security=True;User Instance=True");
dbconnection.Open();

SqlDataAdapter sda = new SqlDataAdapter("SELECT * FROM customer_database", dbconnection);

DataTable dt = new DataTable();
sda.Fill(dt);
GridView.DataSource = dt;
}

private void close_btn_Click(object sender, EventArgs e)
{
this.Close();
}

private void GridView_CellDoubleClick(object sender, DataGridViewCellEventArgs e)
{
Int id = Convert.ToInt32(GridView.Rows[e.RowIndex].Cells[0].Value);
UpdateDatabase ud = new UpdateDatabase(id);
ud.ShowDialog();
}
}
}