ASP.Net สอบถาม วิธีส่งค่าที่ได้ทำการ Checkbox ที่ Gridview 1 ไปที่ Gridview 2 ค่ะ ^ - ^"

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Web;
using System.Web.Services;
using System.Xml;
using System.Xml.Serialization;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
using System.Text;
using System.Web.Services.Protocols;
using System.Web.Configuration;
using System.Data.OleDb;
using System.Security;
using CrystalDecisions.CrystalReports.Engine;
using CrystalDecisions.Web;
using CrystalDecisions.Shared;
using System.Collections;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Globalization;
using System.Threading;

 protected void Page_Load(object sender, EventArgs e)
        {

            if (!IsPostBack)
            {
                BindGridview();
                BindSecondGrid();
            }

        }

        protected void BindGridview()
        {

            string strConn = "Data Source=KKD0623HIT\\SQLEXPRESS ;Persist Security Info=True;Initial Catalog=mydatabase;User ID=sa;password=12345";
            string query = "SELECT CustomerID , Name , Email";
            query += " FROM Customer ";

            DataTable dt = new DataTable();
            SqlDataAdapter adp = new SqlDataAdapter(query, strConn);
            adp.Fill(dt);
            adp.Dispose();

            gvDetails.DataSource = dt;
            gvDetails.DataBind();
        }
        protected void chkSelect_CheckChanged(object sender, EventArgs e)
        {
            GetSelectedRows();
            BindSecondGrid();
        }
        protected void BindSecondGrid()
        {
            DataTable dt = (DataTable)ViewState["GetRecords"];
            gvShow.DataSource = dt;
            gvShow.DataBind();
        }
        private void GetSelectedRows()
        {
            DataTable dt;
            if (ViewState["GetRecords"] != null)
                dt = (DataTable)ViewState["GetRecords"];
            else
                dt = CreateTable();
            for (int i = 0; i < gvDetails.Rows.Count; i++)
            {
                CheckBox chk = (CheckBox)gvDetails.Rows[i].Cells[0].FindControl("checkselect");
                if (chk.Checked)
                {
                    dt = AddGridRow(gvDetails.Rows[i], dt);
                }
                else
                {
                    dt = RemoveRow(gvDetails.Rows[i], dt);
                }
            }
            ViewState["GetRecords"] = dt;
        }
        private DataTable CreateTable()
        {
            DataTable dt = new DataTable();
            dt.Columns.Add("CustomerID");
            dt.Columns.Add("Name");
            dt.Columns.Add("Email");

            dt.AcceptChanges();
            return dt;
        }
        private DataTable AddGridRow(GridViewRow gvRow, DataTable dt)
        {
            DataRow[] dr = dt.Select("CustomerID = '" + gvRow.Cells[1].Text + "'");
            if (dr.Length <= 0)
            {
                dt.Rows.Add();
                int rowscount = dt.Rows.Count - 1;
                dt.Rows[rowscount]["CustomerID"] = gvRow.Cells[1].Text;
                dt.Rows[rowscount]["Name"] = gvRow.Cells[2].Text;
                dt.Rows[rowscount]["Email"] = gvRow.Cells[3].Text;

                dt.AcceptChanges();
            }
            return dt;
        }
        private DataTable RemoveRow(GridViewRow gvRow, DataTable dt)
        {
            DataRow[] dr = dt.Select("CustomerID = '" + gvRow.Cells[1].Text + "'");
            if (dr.Length > 0)
            {
                dt.Rows.Remove(dr[0]);
                dt.AcceptChanges();
            }
            return dt;
        }

    }
}