How to Insert Multiple Rows from gridview

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataKeyNames="owner_id,vehicle_id,regno" DataSourceID="SqlDataSource1">
                       <Columns>
                           <asp:BoundField DataField="owner_id" HeaderText="owner_id" ReadOnly="True" SortExpression="owner_id" />
                           <asp:BoundField DataField="vehicle_id" HeaderText="vehicle_id" ReadOnly="True" SortExpression="vehicle_id" />
                           <asp:BoundField DataField="regno" HeaderText="regno" ReadOnly="True" SortExpression="regno" />
                           <asp:BoundField DataField="insurancedate" HeaderText="insurancedate" SortExpression="insurancedate" />
                           <asp:BoundField DataField="status" HeaderText="status" SortExpression="status" />
                           <asp:BoundField DataField="fromdate" HeaderText="fromdate" SortExpression="fromdate" />
                           <asp:BoundField DataField="todate" HeaderText="todate" SortExpression="todate" />
                           <asp:BoundField DataField="startplace" HeaderText="startplace" SortExpression="startplace" />
                           <asp:BoundField DataField="endplace" HeaderText="endplace" SortExpression="endplace" />
                           <asp:BoundField DataField="Price" HeaderText="Price" SortExpression="Price" />

                           <asp:BoundField DataField="driver" HeaderText="driver" SortExpression="driver" />


                            <asp:TemplateField HeaderText="Driver">
                               <itemtemplate>
                                <asp:textbox id="driver" runat="server"></asp:textbox>
                                </itemtemplate>
                           </asp:TemplateField>

                            <asp:TemplateField HeaderText="FromDate">
                               <itemtemplate>
                                <asp:textbox id="fromdate" runat="server"></asp:textbox>
                                </itemtemplate>
                           </asp:TemplateField>

                            <asp:TemplateField HeaderText="ToDate">
                               <itemtemplate>
                                <asp:textbox id="todate" runat="server"></asp:textbox>
                                </itemtemplate>
                           </asp:TemplateField>

                            <asp:TemplateField HeaderText="StartPlace">
                               <itemtemplate>
                                <asp:textbox id="startplace" runat="server"></asp:textbox>
                                </itemtemplate>
                           </asp:TemplateField>

                            <asp:TemplateField HeaderText="EndPlace">
                               <itemtemplate>
                                <asp:textbox id="endplace" runat="server"></asp:textbox>
                                </itemtemplate>
                           </asp:TemplateField>

                            <asp:TemplateField HeaderText="Price">
                               <itemtemplate>
                                <asp:textbox id="price" runat="server"></asp:textbox>
                                </itemtemplate>
                           </asp:TemplateField>

                       </Columns>

                   </asp:GridView>

using MySql.Data.MySqlClient;
using System;
using System.Collections.Generic;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class bookcars : System.Web.UI.Page
{
    MySqlConnection conn = new MySqlConnection(ConfigurationManager.ConnectionStrings["tourConnectionString"].ConnectionString);
    string a, b, c, d, f, g, h;
    int i, j;
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void Button4_Click(object sender, EventArgs e)
    {          
        
            foreach (GridViewRow row in GridView1.Rows)
            {
                Response.Write("hii");

                if (row.RowType == DataControlRowType.DataRow)
                {
                    i = Convert.ToInt32(row.Cells[0].Text);
                    j = Convert.ToInt32(row.Cells[1].Text);
                    h = Convert.ToString(row.Cells[2].Text);

                    Response.Write("hello");
                    TextBox driver = row.FindControl("Driver") as TextBox;
                    TextBox fromdate = row.FindControl("FromDate") as TextBox;
                    TextBox todate = row.FindControl("ToDate") as TextBox;
                    TextBox startplace = row.FindControl("StartPlace") as TextBox;
                    TextBox endplace = row.FindControl("EndPlace") as TextBox;
                    TextBox price = row.FindControl("Price") as TextBox;
                    Response.Write("howz");
                    try
                    {
                        try
                        {
                            if (driver.Text != " ")
                            {
                                a = Convert.ToString(driver.Text);
                            }
                            else
                                a = null;
                        }
                        catch
                        {
                            a = null;
                        }
                        try
                        {
                            if (fromdate.Text != " ")
                            {
                                b = Convert.ToString(fromdate.Text);
                            }
                            else
                                b = null;
                        }
                        catch
                        {
                            b = null;
                        }
                        try
                        {
                            if (todate.Text != " ")
                            {
                                c = Convert.ToString(todate.Text);
                            }
                            else
                                c = null;
                        }
                        catch
                        {
                            c = null;
                        }
                        try
                        {
                            if (startplace.Text != " ")
                            {
                                d = Convert.ToString(startplace.Text);
                            }
                            else
                                d = null;
                        }
                        catch
                        {
                            d = null;
                        }
                        try
                        {
                            if (endplace.Text != " ")
                            {
                                f = Convert.ToString(endplace.Text);
                            }
                            else
                                f = null;
                        }
                        catch
                        {
                            f = null;
                        }
                        try
                        {
                            if (price.Text != " ")
                            {
                                g = Convert.ToString(price.Text);
                            }
                            else
                                g = null;
                        }
                        catch
                        {
                            g = null;
                        }
                        try
                        {
                            Response.Write("u");
                            conn.Open();
                            MySqlCommand cmd = new MySqlCommand("update owner_vehicle Set fromdate=@fromdate,todate=@todate,startplace=@startplace,endplace=@endplace,Price=@Price,status=@status,driver=@driver where owner_id=@owner_id && vehicle_id=@vehicle_id && regno=@regno", conn);
                            cmd.Parameters.AddWithValue("@fromdate", b);
                            cmd.Parameters.AddWithValue("@todate", c);
                            cmd.Parameters.AddWithValue("@startplace", d);
                            cmd.Parameters.AddWithValue("@endplace", f);
                            cmd.Parameters.AddWithValue("@Price", g);
                            cmd.Parameters.AddWithValue("@status", "yes");
                            cmd.Parameters.AddWithValue("@driver", a);
                            cmd.Parameters.AddWithValue("@owner_id", i);
                            cmd.Parameters.AddWithValue("@vehicle_id", j);
                            cmd.Parameters.AddWithValue("@regno", h);
                            cmd.ExecuteNonQuery();
                            Response.Write("fine");
                        }
                        catch { }

                        Response.Write("hi/hello/howz");

                    }
                    catch { }
                }

           // }
        }      
    }
}