'qnetworkreply' has not been declared

This is my code but it is giving me error "'qnetworkreply' has not been declared" .Can any one tell why it is so

#ifndef ApplicationUI_HPP_
#define ApplicationUI_HPP_

#include <QObject>
namespace bb { namespace cascades { class Application; }}

class ApplicationUI : public QObject
{
    Q_OBJECT
public:
    ApplicationUI(bb::cascades::Application *app);
    virtual ~ApplicationUI() {}

    public slots:
    void onResult(QNetworkReply*);
};


#endif 

Did you add : QT += network in your .pro file ?