Help me Plese !! ค่าที่เก็บใน Session ไม่ส่งค่าในหน้าถัดไป

public partial class Formsubmit1 : System.Web.UI.Page
{
    DataTable myDataTable1 = new DataTable();
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!(Page.IsPostBack))
        {
            myDataTable1 = CreateColumnTable();
            //Response.Write("New Teble");
            Session["myData1"] = myDataTable1;
            GridView1.DataBind();

        }
        else
            myDataTable1 = (DataTable)Session["myData1"];

    }
    protected void ImageButton1_Click(object sender, ImageClickEventArgs e)
    {
        DataRow dr = myDataTable1.NewRow();
        dr["Name_th"] = TextBox1.Text.ToString();
        dr["Name_eng"] = TextBox2.Text.ToString();
        dr["Type"] = DropDownList1.SelectedValue.ToString();
        dr["Type_edu"] = DropDownList2.SelectedValue.ToString();
        dr["Activity"] = DropDownList3.SelectedValue.ToString();
        dr["Major"] = DropDownList4.SelectedValue.ToString();
        dr["Year"]= DropDownList5.SelectedValue.ToString();

        myDataTable1.Rows.Add(dr);
        GridView1.DataSource = myDataTable1;
        GridView1.DataBind();
        Session["myData1"] = myDataTable1;
        //Response.Write(myDataTable.Rows.Count);

    }
    private DataTable CreateColumnTable()
    {
        DataTable dt;
        if (Session["myData1"] != null)
        {
            dt = (DataTable)Session["myData1"];
        }
        else
            dt = new DataTable();
        DataColumn dc = new DataColumn();
        dc.ColumnName = "Name_th";
        dt.Columns.Add(dc);
        dc = new DataColumn();
        dc.ColumnName = "Name_eng";
        dt.Columns.Add(dc);
        dc = new DataColumn();
        dc.ColumnName = "Type";
        dt.Columns.Add(dc);
        dc = new DataColumn();
        dc.ColumnName = "Type_edu";
        dt.Columns.Add(dc);
        dc = new DataColumn();
        dc.ColumnName = "Activity";
        dt.Columns.Add(dc);
        dc = new DataColumn();
        dc.ColumnName = "Major";
        dt.Columns.Add(dc);
        dc = new DataColumn();
        dc.ColumnName = "Year";
        dt.Columns.Add(dc);

        return dt;
    }
}// End Class

 DataTable myDataTable2 = new DataTable();
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!(Page.IsPostBack))
        {
            myDataTable2 = CreateColumnTable();
            Session["myData2"] = myDataTable2;
        }
        else
            myDataTable2 = (DataTable)Session["myData2"];
    }
    protected void ImageButton1_Click(object sender, ImageClickEventArgs e)
    {

        DataRow dr = myDataTable2.NewRow();
        dr["publication_id"] = TextBox1.Text.ToString();
        dr["journal_print"] = TextBox2.Text.ToString();
        dr["research_publication"] = TextBox3.Text.ToString();
        dr["importance"] = RadioButtonList1.SelectedValue.ToString();
        dr["research_reference"] = TextBox4.Text.ToString();
        dr["research_stap"] = TextBox5.Text.ToString();
                                
        myDataTable2.Rows.Add(dr);
        GridView1.DataSource = myDataTable2;
        GridView1.DataBind();
        Session["myData2"] = myDataTable2;
    }


    private DataTable CreateColumnTable()
    {
        DataTable dt;
        if (Session["myData2"] != null)
        {
            dt = (DataTable)Session["myData2"];
        }
        else
            dt = new DataTable();
        DataColumn dc = new DataColumn();
        dc.ColumnName = "publication_id";
        dt.Columns.Add(dc);
        dc = new DataColumn();
        dc.ColumnName = "journal_print";
        dt.Columns.Add(dc);
        dc = new DataColumn();
        dc.ColumnName = "research_publication";
        dt.Columns.Add(dc);
        dc = new DataColumn();
        dc.ColumnName = "importance";
        dt.Columns.Add(dc);
        dc = new DataColumn();

        dc = new DataColumn();
        dc.ColumnName = "research_reference";
        dt.Columns.Add(dc);
        dc = new DataColumn();
        dc.ColumnName = "research_stap";
        dt.Columns.Add(dc);

        return dt;
    }

}// End Class

 DataTable myDataTable3 = new DataTable();
    
    protected void Page_Load(object sender, EventArgs e)
    {
        
        if (!(Page.IsPostBack))
        {
            myDataTable3 = CreateColumnTable();
            //Response.Write("New Teble");
            Session["myData3"] = myDataTable3;
        }
        else
            myDataTable3 = (DataTable)Session["myData3"];
            GridView1.DataBind();
        
    }

    private DataTable CreateColumnTable()
    {
        DataTable dt;
        if (Session["myData3"] != null)
        {
            dt = (DataTable)Session["myData3"];
        }
        else
            dt = new DataTable();
        DataColumn dc = new DataColumn();
        dc.ColumnName = "Activity2";
        dt.Columns.Add(dc);
        dc = new DataColumn();
        dc.ColumnName = "Start_Date";
        dt.Columns.Add(dc);
        dc = new DataColumn();
        dc.ColumnName = "End_Date";
        dt.Columns.Add(dc);

        return dt;
    }
    protected void ImageButton1_Click(object sender, ImageClickEventArgs e)
    { 
        DataRow dr = myDataTable3.NewRow();
        dr["Activity2"] = TextBox1.Text.ToString();
        dr["Start_Date"] = TextBox2.Text.ToString();
        dr["End_Date"] = TextBox3.Text.ToString();

        myDataTable3.Rows.Add(dr);
        GridView1.DataSource = myDataTable3;
        GridView1.DataBind();
        //Response.Write(myDataTable.Rows.Count);
    }
}

public partial class Formsubmit4 : System.Web.UI.Page
{
    string strConn = ConfigurationManager.ConnectionStrings["Research_DBConnectionString"].ToString();

    DataTable myDataTable1;
    DataTable myDataTable2;
    DataTable myDataTable3;
    DataTable myDataTable4 = new DataTable();

    protected void Page_Load(object sender, EventArgs e)
    {

        if (!(Page.IsPostBack))
        {
            myDataTable4 = CreateColumnTable();
            //Response.Write("New Teble");
            Session["myData1"] = myDataTable1;
            Session["myData2"] = myDataTable2;
            Session["myData3"] = myDataTable3;
            Session["myData4"] = myDataTable4;
        }
        else
                myDataTable1 = (DataTable)Session["myData1"];
                myDataTable2 = (DataTable)Session["myData2"];
                myDataTable3 = (DataTable)Session["myData3"];
                myDataTable4 = (DataTable)Session["myData4"];

                GridView1.DataBind();
           

    }

    private DataTable CreateColumnTable()
    {
        DataTable dt;
        if (Session["myData4"] != null)
        {
            dt = (DataTable)Session["myData4"];
        }
        else
            dt = new DataTable();
            DataColumn dc = new DataColumn();
                dc.ColumnName = "Boss";
                dt.Columns.Add(dc);
                dc = new DataColumn();
                dc.ColumnName = "Firstname";
                dt.Columns.Add(dc);
                dc = new DataColumn();
                dc.ColumnName = "Lastname";
                dt.Columns.Add(dc);

        return dt;
    }

    protected void ImageButton1_Click(object sender, ImageClickEventArgs e)
    {
        


        DataRow dr = myDataTable4.NewRow();
        dr["Boss"] = DropDownList1.SelectedValue.ToString();
        dr["Firstname"] = TextBox1.Text.ToString();
        dr["Lastname"] = TextBox2.Text.ToString();
        

        myDataTable4.Rows.Add(dr);
        GridView1.DataSource = myDataTable4;
        GridView1.DataBind();
        Session["myData1"] = myDataTable1;
        Session["myData2"] = myDataTable2;
        Session["myData3"] = myDataTable3;
        Session["myData4"] = myDataTable4;

        //Response.Write(myDataTable.Rows.Count);
    }

    
    protected void ImageButton2_Click(object sender, ImageClickEventArgs e)
    {


        myDataTable1 = (DataTable)Session["myData1"];
        myDataTable2 = (DataTable)Session["myData2"];
        myDataTable3 = (DataTable)Session["myData3"];


        SqlConnection conn = new SqlConnection(strConn);
        conn.Open();
        string ins = @"Insert in to tb_research(
                        research_id,
                        research_code,
                        name_t,
                        name_e,
                        start_date,
                        end_date,
                        budget_id,
                        type_id,
                        education_id,
                        activity_id,
                        @major_id,
                        status_id,
                        publication_id,
                        journal_print,
                        research_publication,
                        importance,
                        research_reference,
                        research_stap) 
                             Values(@research_id,research_code,@name_t,@name_e,@start_date,@end_date,@budget_id,@type_id,@education_id,
                                    @activity_id,@major_id,@status_id,@publication_id,@journal_print,@research_publication,
                                    @importance,@research_reference,@research_stap)";

        SqlCommand sqlcmd = new SqlCommand(ins, conn);
        //string id_cars = CreateIDArticle();
        int id_type = Convert.ToInt32(myDataTable1.Rows[0].ItemArray[3].ToString());
        int id_education = Convert.ToInt32(myDataTable1.Rows[0].ItemArray[4].ToString());
        int id_activity = Convert.ToInt32(myDataTable1.Rows[0].ItemArray[5].ToString());
        int id_major = Convert.ToInt32(myDataTable1.Rows[0].ItemArray[6].ToString());
        int id_budget = Convert.ToInt32(myDataTable1.Rows[0].ItemArray[7].ToString());
        int id_pubblication = Convert.ToInt32(myDataTable2.Rows[0].ItemArray[0].ToString());

        sqlcmd.Parameters.AddWithValue("@research_id",'1');
        sqlcmd.Parameters.AddWithValue("@research_code",'1');

        sqlcmd.Parameters.AddWithValue("@name_t",myDataTable1.Rows[0].ItemArray[0].ToString());
        sqlcmd.Parameters.AddWithValue("@name_t",myDataTable1.Rows[0].ItemArray[1].ToString());

        sqlcmd.Parameters.AddWithValue("@start_date",myDataTable3.Rows[0].ItemArray[1].ToString());
        sqlcmd.Parameters.AddWithValue("@end_date",myDataTable3.Rows[0].ItemArray[2].ToString());

        sqlcmd.Parameters.AddWithValue("@type_id",id_type);
        sqlcmd.Parameters.AddWithValue("@education_id",id_education);
        sqlcmd.Parameters.AddWithValue("@activity_id",id_activity);
        sqlcmd.Parameters.AddWithValue("@major_id",id_major);
        sqlcmd.Parameters.AddWithValue("@budget_id",id_budget);
        
        sqlcmd.Parameters.AddWithValue("@status_id",'1');

        sqlcmd.Parameters.AddWithValue("@publication_id",id_pubblication);
        sqlcmd.Parameters.AddWithValue("@journal_print",myDataTable2.Rows[0].ItemArray[1].ToString());
        sqlcmd.Parameters.AddWithValue("@research_publication",myDataTable2.Rows[0].ItemArray[2].ToString());
        sqlcmd.Parameters.AddWithValue("@importance",myDataTable2.Rows[0].ItemArray[3].ToString());
        sqlcmd.Parameters.AddWithValue("@research_reference",myDataTable2.Rows[0].ItemArray[4].ToString());
        sqlcmd.Parameters.AddWithValue("@research_stap", myDataTable2.Rows[0].ItemArray[5].ToString());
        //table1

//tb_activity
//tb_work


       
        //sqlcmd.Parameters.AddWithValue("@ID", id_cars);

        sqlcmd.ExecuteNonQuery();


        conn.Close();
    }