if($_POST["action"] == "add_side")
  {

       foreach($_SESSION["shopping_cart"] as $keys => $values)
       {
            if($_SESSION["shopping_cart"][$keys]['product_id'] ==
  $_POST["product_id"])
            {
                 foreach($_SESSION["shopping_cart"] as $key => $values)
       {
      $_SESSION["shopping_cart"][$key]['side_name'] =
  $_POST["side_name"];


                 }

       }
       }
  }