public void add_dtCart() { if (cart1 != null) { DataTable ca = Session["guest"] as DataTable; foreach (RepeaterItem it in rpguest.Items) { Label n1 = (Label)it.FindControl("lblID"); TextBox n2 = (TextBox)it.FindControl("tbqty"); Label n3 = (Label)it.FindControl("lblsum"); Label n4 = (Label)it.FindControl("lbltsum"); dc = new cart_detail(); dc.id_cart = cart1.id_cart; dc.id_pro = Convert.ToInt32(n1.Text); dc.quantity = Convert.ToInt32(n2.Text); dc.total_price = float.Parse(n3.Text); //n4.Text = tbguest.Compute("Sum(lblsum)", "").ToString(); cl.AdddtCart(dc); } } }