what is the handiest way to update only the updated rows (only the checkbox column) in this gridview? what is a handy way to check wether the row was updated?
c#
public partial class _Default : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            List<customer> listCustomer = new List<customer>();
            customer cust1 = new customer(){name="fred",email="
[email protected]",jobless="true"};
            customer cust2 = new customer(){name="
mark",email="
[email protected]",jobless="false"};
            listCustomer.Add(cust1);
            listCustomer.Add(cust2);
            GridView1.DataSource=listCustomer;
            GridView1.DataBind();
        }
    }
protected void btnUpdate_Click1(object sender, EventArgs e)
        {
            foreach (GridViewRow rw in GridView1.Rows)
            {
                CheckBox thiscontrol = (CheckBox)rw.Cells[0].FindControl("cb");
                var ch = thiscontrol.Checked;
                //only update the updated rows?
            }
        }
    public class customer
    {
        public string name { get; set; }
        public string email { get; set; }
        public string jobless { get; set; }
    }
html
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="gridviewUpdate._Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:GridView ID="GridView1" AutoGenerateColumns="false" runat="server">
            <Columns>
                <asp:TemplateField>
                    <ItemTemplate>
                        <asp:CheckBox ID="jobless" runat="server" Checked='<%# Eval("jobless").ToString().Equals("true") %>' />
                    </ItemTemplate>
                </asp:TemplateField>
                <asp:BoundField DataField="email" />
                <asp:BoundField DataField="name" />
            </Columns>
        </asp:GridView>
    </div>