Wingtip Toys sample in VB

Hi All...
Another noob here, I've been trying to 'do' the Wingtip Toys sample in VB.
I have downloaded the code in both C# and VB and have been substituting the code from the VB version whilst following th C# tutorial.
I'm now at the first try at running the code at the end of this page.
http://www.asp.net/web-forms/tutorials/aspnet-45/getting-started-with-aspnet-45-web-forms/ui_and_navigation
When I run the page I am getting the following error
"Compiler Error Message: BC30002: Type 'WingtipToys.Models.Category' is not defined."
Line 84: <ItemTemplate> Line 85: <b style="font-size: large; font-style: normal"> Line 86: <a href="/ProductList.aspx?id=< ...