สอบถามปัญหาการส่งค่าจาก textboxและ dropdownlist ใช้ Query String แล้วไม่ขึ้นค่ะ

            <asp:ListItem Value=" ">กรุณาเลือก</asp:ListItem>
 <asp:ListItem Value="RELAX8332">RELAX : 8332</asp:ListItem>
  <asp:ListItem Value="RELAX7439">RELAX : 7439</asp:ListItem>
   <asp:ListItem Value="RELAX7663">RELAX : 7663</asp:ListItem>
    <asp:ListItem Value="RELAX7730">RELAX : 7730</asp:ListItem>
     <asp:ListItem Value="RELAX7607">RELAX : 7607</asp:ListItem>
      <asp:ListItem Value="ACTIVE8045">ACTIVE : 8045</asp:ListItem>
      <asp:ListItem Value="ACTIVE7990">ACTIVE : 7990</asp:ListItem>
      <asp:ListItem Value="ACTIVE7910">ACTIVE : 7910</asp:ListItem>
      <asp:ListItem Value="ACTIVE7774">ACTIVE : 7774</asp:ListItem>
      <asp:ListItem Value="ACTIVE7776">ACTIVE : 7776</asp:ListItem>
 
</asp:DropDownList>

        protected void DropdownList1_SelectedIndexChanged(object sender, EventArgs e)
        {
            //this.lblText2.Text = this.DropDownList2.SelectedItem.Text;
            this.Label2.Text = this.DropdownList1.SelectedItem.Text;
        }

        protected void Button1_Click(object sender, EventArgs e)
        {
            string value1 = DropdownList1.SelectedValue;
            Response.Redirect("calculate.aspx?v1=" + value1);
            //Response.Redirect(DropdownList1.SelectedValue);
        }

protected void Page_Load(object sender, EventArgs e)
        {
            string val1= Request.QueryString["value1"];
            Label2.Text = val1;
        }

 protected void Button4_click(object sender, EventArgs e)
        {
            string v1 = TextBox1.Text;
            string v2 = TextBox2.Text;
            string v3 = TextBox3.Text;
            string v4 = TextBox4.Text;
            string v5 = TextBox5.Text;
            string v6 = TextBox6.Text;
            double a = Convert.ToDouble(v1);
            double b = Convert.ToDouble(v2);
            double c = Convert.ToDouble(v3);
            double d = Convert.ToDouble(v4);
            double f = Convert.ToDouble(v5);
            double g = Convert.ToDouble(v6);

            double walla = a * b;
            double doora = c * 0.8 * 2;
            double wina = d * 0.6;
            double ota = f * g;

            string value1 = Convert.ToString(walla);
            string value2 = Convert.ToString(doora);
            string value3 = Convert.ToString(wina);
            string value4 = Convert.ToString(ota);
       

            //ส่งค่า value

            Response.Redirect("result.aspx?v1=" + value1 + "&v2=" + value2 + "&v3=" + value3 + "&v4=" + value4);

        }

string value1 = Request.QueryString["value1"];
            string value2 = Request.QueryString["value2"];
            string value3 = Request.QueryString["value3"];
            string value4 = Request.QueryString["value4"];

            Label2.Text = value1;
            Label3.Text = value2;
            Label4.Text = value3;
            Label5.Text = value4;