external libraries & .h

[Massinissa]

Hi!
I built and configured Itk with cmake using msys compiler and it generated me a bin file, lib file & include file which it has many .h.
I added the .h files and lib file(.dll.a) in my NetBeans project. everything was ok from here.
When I started programming, for example here is a part of my code:

int main(int argc, char *argv[]) {
// initialize resources, if needed
// Q_INIT_RESOURCE(resfile);

typedef unsigned char PixelType;
typedef itk::ImageFileReader<PixelType, 2> TypeReader;

QApplication app(argc, argv);
// create and show your widgets here
return app.exec();
}

when I write itk:: it shows me a bunch of object or subclass that I can chose. It seems working but when I build the project. I get this error:

error: 'itk' has not been declared

How can I fix it??

thank you for your help!

Massi