New Post: Problem with dynamic Type

hi, i have this source:
http://pastebin.de/124823

i add this class to the engine:

se.AddHostType("NativeLibraryImporter", typeof(DynamicDllImport));

Usage:

dynamic c =  js.Evaluate(@"var o = new NativeLibraryImporter(""user32.dll"");");

but c is undefined, and when i use MessageBox function with o.MessageBox then i get error: method.
it work with c#, what is wrong?

thank you