public bool Login()
 {
     try
     {
         string username = Input("Username: "******"Password: ");
         User   user     = service.Authenticate(username, password);
         if (user != null)
         {
             currentUser = user;
         }
         return(user != null);
     }
     catch (RepositoryException e)
     {
         System.Console.WriteLine(e.Message);
         return(false);
     }
 }