I've bought the book ASP.NET ECommerce Programming - Problem, Design, Solution.

I've downloaded and installed the code and database from WROX.COM, but I have one problem. When i'm trying to add products to the cart, I get the following error:

Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.

Source Error:


Line 248: oi.SKU = (string)currentRow["SKU"];
Line 249: oi.Special = false;
Line 250: currentOrder.OrderItems.Add( oi );
Line 251:
Line 252: currentRunningTotal += extPrice;


Source File: C:\Inetpub\wwwroot\GWSetup\ShoppingCart.aspx.cs Line: 250

Plz help!