If your controls are private or protected which they are by default then another class won't see them. You could make them public but this would be a bad design.

If you are using bound controls look at the ErrorProvider class. http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfsystemwindowsformserrorproviderclasstopic.asp
Just have the business rules set the errors on your DataSet and the ErrorProvider will pick up on it.

>Again, I just want to create a class of rules for each form, where the class can examine the form object and 'see' all the controls underneath. That way, the form itself has nothing more than the controls and function calls to the form class logic. It's one of these cases where I knew how to do this in VFP, but haven't figured out how to implement in .NET.
>
>Thanks,
>Kevin