Oшибка: 'pobj' was not declared in this scope [требует правки]

Разбираю пример из учебника и столкнулся сразу же с ошибкой

/home/anton/Qt/untitled1/main.cpp:39: ошибка: 'pobj' was not declared in this scope
     pobj->setProperty("readOnly", true);
     ^

..

class MyClass : public QObject {
    Q_OBJECT
    Q_PROPERTY(bool ReadOnly READ isReadOnly WRITE setReadOnly)
private:
    bool m_bReadOnly;
public:
    MyClass (QObject* pobj = 0) : QObject(pobj), m_bReadOnly(false)
    {
    }
public:
    void setReadOnly(bool bReadOnly)
    {
        m_bReadOnly=bReadOnly;
    }
    bool isReadOnly() const
    {
        return m_bReadOnly;
    }
};

И далее программа

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
   ...
    pobj->setProperty("readOnly", true);
    bool bReadOnly=pobj->property("readOnly").toBool();

    return app.exec();
}