[SerializableAttribute()] 
public class Order.DebuggingInfo 

class MyPage : System.Web.UI.Page
{
   private static void LogEvent(Dynamicweb.eCommerce.Orders.Order order, string message, params object[] @params)
   {
       string orderID = null;
       if (order == null || string.IsNullOrEmpty(order.ID))
       {
           orderID = "<No order>";
       }
       else
       {
           orderID = order.ID;
       }
       string printedMessage = string.Format("Order {0}: {1}", orderID, string.Format(message, @params));
       LogToFile.Log(printedMessage, "/eCom/CartV2/Events", LogToFile.LogType.ManyEntriesPerFile);

       //Also save debugging info on the order
       if (order != null)
       {
           order.DebuggingInfos.Add(new Dynamicweb.eCommerce.Orders.Order.DebuggingInfo(printedMessage));
           order.SaveDebuggingInfos();
       }
   }
}