VS 2008 - Refactoring Presentation Layer

I've been working to refactor my code and ended up with a quite clean main BLL class that has only a few manager classes that pass information between eachother. They handle separate tasks/areas like socket connection, data, etc. It's only one instance of each of these manager objects, so I believe maybe the base layout is a structural singleton (?) ..but not sure. This seems to give quite good oversight and a clean separation of PL/BLL as the main form only access the BLL through one instance of a single class. But now I'm trying to figure out how to lay out the presentation layer. So with this I would like to understand a few points: Do you have all controls as members of the form class, or can you make sub classes where some controls only exist on lower levels? Like for example if you have a tab where all controls only interact with each other, and not the rest of the form, would it then be possible to make this a separate class that holds both controls and additional logic ? The first problem I get when trying this is with the events, as if I simply move an event handler method to another class than the form class, I get the message: Handles clause requires a WithEvents variable defined in the containing type or one of its base types.What does this mean? and is there an easy way around this? I would like to understand how a slightly more complex PL is designed, so I know what direction to move in for studying/developing this.