passing parameters between pages

hi 

i have a problem in my code, i am trying to read records from database and beside each record i want to place a button  which redirecting me to another page , i want this button to send also the id of the record besides it but the problem is that it sends the id of the last record always.

here is the code 

if (!Page.IsPostBack)
        {

            string connectionString = WebConfigurationManager.ConnectionStrings["mokattam"].ConnectionString;
            SqlConnection con = new SqlConnection(connectionString);


            try
            {
                con.Open();
                SqlCommand cmd = new SqlCommand("SELECT subject, body, id FROM complains", con);
                cmd.ExecuteScalar();
                SqlDataReader dr = cmd.ExecuteReader();
                int i = 0;


                
                     while (dr.Read()){
                   
                        AccordionPane ap = new AccordionPane();
                        Button b = new Button();
                        ap.ID = "ap" + i;
                        b.ID = "b" + i;
                        b.Text = "Reply";
                        string url = "reply.aspx?id=" + Session["id"];
                        b.PostBackUrl = url;
                        ap.HeaderContainer.Controls.Add(new LiteralControl(dr["subject"].ToString()));
                        ap.ContentContainer.Controls.Add(new LiteralControl(dr["body"].ToString()));
                        ap.ContentContainer.Controls.Add(new LiteralControl("</br>"));
                        ap.ContentContainer.Controls.Add(b);

                        Accordion1.Panes.Add(ap);
                        i++;
                    
                }

               
                dr.Close();
                




            }
            catch (Exception err)
            {
                Response.Write(err.Message);
            }
            finally
            {

                con.Close();


            }
        }
    }

where did you assign the value for your session?

    Protected Sub Button1_Click(ByVal sender As Object, ByVal e As EventArgs) Handles Button1.Click
Response.Redirect("DesiredPage.aspx?id=" + Session("UserID"))
    End Sub

Why u r not using

string url = "reply.aspx?id=" + dr["id"].ToString();

instead of

string url = "reply.aspx?id=" + Session["id"];

I think It will work as u need.