WPF project, add existing item as link

Hi.

I have two solutions for .NET2 and .NET4 and NET4 solution has projects that use files (.cs etc) from .NET2 solution. I have create a WPF application project in my .NET4 solution and trying to add files (App.xaml and WindowMain.xaml) from .NET2 solution.

The problem is that when I delete the default App and WindowMain files and try to add existing files as link (from .NET2 solution project) I cannot build the .NET4 solution's project. I get an error message saying that the Main methdod does not exist.

Is it even possible to do this when dealing with WPF projects? When I do the same with Windows Form projects, everything works just fine.

Best regards, 

-J-