class B: public QWizardPage
{
public:
    QString text();
    void    setText(const QString& newText);
private:
    QString m_text;
};

void QWizardPage::registerField ( const QString & name, QWidget * widget, const char * property = 0, const char * changedSignal = 0 )   [protected]
Creates a field called name associated with the given property of the given widget. From then on, that property becomes accessible using field() and setField().

Fields are global to the entire wizard and make it easy for any single page to access information stored by another page, without having to put all the logic in QWizard or having the pages know explicitly about each other.