insert multiple rows from gridview to database

if (Convert.ToDecimal(Label1.Text) > 0)
       {
         if (Convert.ToDecimal(Label1.Text) > 0)
        {
            string proid = Application["id"].ToString();
            con.Open();
            da = new SqlDataAdapter("select tpd.productid,tpd.productname,tpd.ProductImage,tpd.price,tpd.qty,tpd.totalcost,tpd.cdate from rsa_addtocart tpd where tpd.productid=" + proid + " ", con);
            ds = new DataSet();
            da.Fill(ds, "tbl_tpd");
            if (ds.Tables.Count > 0 && ds.Tables["tbl_tpd"].Rows.Count > 0)
           {

               using (var command = new SqlCommand("insert into rsa_Orderconfirmation(UserId, productid, productname, ProductImage, price, qty, totalcost, cdate) values (@UserId, @productid, @productname, @ProductImage, @price, @qty, @totalcost, @cdate)", con))
               {
                   for (int z = 0; z < this.Gridcart.Rows.Count; z++)
                   {
                       command.Parameters.Clear();
                       command.Parameters.AddWithValue("@UserId", Session["users"]);
                       command.Parameters.AddWithValue("@productid", ds.Tables[0].Rows[0][0]);
                       command.Parameters.AddWithValue("@productname", ds.Tables[0].Rows[0][1]);
                       command.Parameters.AddWithValue("@ProductImage", ds.Tables[0].Rows[0][2]);
                       command.Parameters.AddWithValue("@price", ds.Tables[0].Rows[0][3]);
                       command.Parameters.AddWithValue("@qty", ds.Tables[0].Rows[0][4]);
                       command.Parameters.AddWithValue("@totalcost", ds.Tables[0].Rows[0][5]);
                       command.Parameters.AddWithValue("@cdate", DateTime.Now);

                       if (con.State != ConnectionState.Open)
                       {
                           con.Open();
                           try
                           {
                               command.ExecuteNonQuery();
                           }
                           finally
                           {
                               con.Close();
                           }
                       }
                       else
                       {
                           command.ExecuteNonQuery();
                       }
                   }

                       Response.Redirect("~/BillingDetails.aspx");
                       con.Close();
                   }
            }
            }