Entity Framework 6 - Knowledge Base (KB)

How can I get around the problem "The name 'ConfigurationManager' does not exist in the current context"?

I am using VS2008. I have a project connect with a database and the connection string is read from App.config via ConfigurationManager. We are using L2E....Now I added a helper project, AndeDataViewer, to have a simple UI to display data from the database...