Problem with building the project

Jan 27, 2009 at 3:15 PM
I'm trying to build the project and have error like
type or namespace 'DashboardBusiness'  could not be found (are you missing a using directive or an assembly reference?)
type or namespace 'DashboardDataAccess'  could not be found (are you missing a using directive or an assembly reference?)
and so on.
How must I add references? Thanks!