FileAssociationInfo And ProgramAssociationInfo

I'm developing a application for Windows Mobile using C#(.Net Compact Framework 3.5), but I need to associate my program with a file type. When I try to use FileAssociationInfo I'm getting this error: The type or namespace name 'FileAssociationInfo' could not be found (are yo开发者_如何学Gou missing a using directive or an assembly reference?)

What I need to do?

You can download the zip file from Channel 9 containing the FileAssociation solution file and source code (it's the 'Download:' link at the top of the article).