how to use gtk::filechooserbutton with gtkmm

["schmirrwurst free fr" <schmirrwurst free fr>]

I've some problems understanding that ! I've tried the following : 

header file (extract) : 
#include <gtkmm/filechooser.h>
#include <gtkmm/filechooserbutton.h>
class Dialog_Make_Image : public Gtk::Dialog
{
......
private:	
	Partition partition ;
	Gtk::HBox *hbox ;
	Gtk::VBox *vbox ;
	Gtk::Frame *frame ;
	Gtk::FileChooserButton *filechooserb ;
	Gtk::Image *image;
};//class


------------------------------
source file (extract):
-------------------------------
filechooserb = ( new Gtk::FileChooserButton( "Select Target File",
FILE_CHOOSER_ACTION_OPEN));
	
	vbox ->pack_start( * filechooserb ,Gtk::PACK_SHRINK ) ;
	frame ->add( *vbox ) ;
	

---------------------------------

But at compiling, I get an error : FILE_CHOOSER_ACTION_OPEN is not
declared, but it must be in gtkmm/filechooser*.h which are declared in
the source header ??