Visualization with Qt - What is wrong in my code ?

Hello,

I'm new to OpenCascade, I need help in viewing an object in a qt widget, below you can see the code for that, it is very basic, the bottle was created as in the tutorial (I think it is the only Real tutorial for openCascade).

So, what's wrong in my code?

#include <QtCore>
#include <QtGui>
#include <makeBottle.h>
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    // create a Qt window
    QWidget *window = new QWidget();
    
    // create a bottle (TopoDS_Shape)
    TopoDS_Shape myBottle = MakeBottle(70., 120., 30.);
    
    // th DisplayDonnection
    Handle(Aspect_DisplayConnection) aDisplayConnection;
    
    // the GraphicDriver
    Handle(OpenGl_GraphicDriver) aGraphicDriver = new OpenGl_GraphicDriver(aDisplayConnection);
    
    // creating the Viewer
    Handle(V3d_Viewer) aViewer = new V3d_Viewer(aGraphicDriver, Standard_ExtString("my3dViewer"));
    
    // creating a View
    Handle(V3d_View) aView = aViewer->CreateView();

    // creating an Xw_Window (I'm on Ubuntu)
    Handle(Xw_Window) aWindow;
    aWindow = new Xw_Window(aDisplayConnection, window->winId());

    // the Interactive context
    Handle(AIS_InteractiveContext) aContext = new AIS_InteractiveContext(aViewer);
    Handle(AIS_Shape) anAISShape = new AIS_Shape(myBottle);
    aContext->Display(anAISShape);

    aView->SetWindow(aWindow);

    window->show();
    return a.exec();
}

When running the code I get this error:

terminate called after throwing an instance of 'Aspect_WindowDefinitionError'

The program has unexpectedly finished.

I'm using Occt 6.8.0 and Qt 4.8 on Linux Ubuntu 14.04 32bit.

As I see there are many tutorials about geometric manipulation of shapes, but the there is no one tutorial that explains the visualization in a GUI (I've read nearly all the available tutorials and posts in this forum, but nothing works correctly !).