TextboxDataAdd in Gridview Through Database Using Linq in .Net

using System;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
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.Xml.Linq;
using System.Collections.Generic;
using System.Collections;

public partial class _Default : System.Web.UI.Page
{
//linq class empdatacontext
//table emp

    empDataContext ee = new empDataContext();
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            Session["data"] = null;
            if (Session["data"] == null)
            {
                List<emp> emp = new List<emp>();

                GridView1.DataSource = ee.emps.ToList();
                GridView1.DataBind();

            }
            else
            {
                GridView1.DataSource = ee.emps.ToList();
                GridView1.DataBind();

            }
        }
    }
//add in grid
    protected void Button1_Click(object sender, EventArgs e)
    {
        emp em = new emp();
        var v=ee.emps.ToList();
        if (Session["data"] == null)
        {
            em.name = txtname.Text;
            em.address = txtaddress.Text;
            ee.emps.InsertOnSubmit(em);

             v = ee.emps.ToList();
            v.Add(em);
            GridView1.DataSource = v.ToList();
            GridView1.DataBind();
            Session["data"] = v;
            txtname.Text = "";
            txtaddress.Text = "";
        }
        else
        {
            List<emp> k = new List<emp>();
           
            k = (List<emp>)Session["data"];
            em.name = txtname.Text;
            em.address = txtaddress.Text;
            ee.emps.InsertOnSubmit(em);

            //k = ee.emps.ToList();
            k.Add(em);
            GridView1.DataSource = k.ToList();
            GridView1.DataBind();
            Session["data"] = k;

            txtname.Text = "";
            txtaddress.Text = "";



        }
    }
//final submit
    protected void Button2_Click(object sender, EventArgs e)
    {
       
        emp em1 = new emp();
       // var kk = k.ToList();
        var products = ee.emps.ToList();
        ee.emps.DeleteAllOnSubmit(products);
        ee.SubmitChanges();
   


//k = (List<emp>)Session["data"];
        for (int i = 0; i < GridView1.Rows.Count; i++)
        {
            emp em = new emp();
            em.name = GridView1.Rows[i].Cells[0].Text.ToString();
            em.address = GridView1.Rows[i].Cells[1].Text.ToString();

            ee.emps.InsertOnSubmit(em);
            ee.SubmitChanges();
          
        }
       


        GridView1.DataSource = ee.emps.ToList();
            GridView1.DataBind();

        Session["data"] = null;
        txtname.Text = "";
        txtaddress.Text = "";


    }
}