Dear ................!

I have a need of QApplication app(int argc,char **argv) variable (which is declared in main.cpp) in pbPreview_clicked() slot.
/*In dlgtextscroller.h I have defined the slot as follows*/
private slots:
virtual void pbPreview_clicked(QApplication *app);


/*In dlgTextScroller constructor I connected the pbPreview clicked( ) push button signal to dlgTextscroller pbPreview_clicked(app) as follows*/

dlgTextScroller::dlgTextScroller( QApplication *app, QWidget* parent)
: QDialog(parent)
{
setupUi(this);
connect( pbPreview, SIGNAL( clicked() ), this, SLOT( pbPreview_clicked(app) ));
}

void dlgTextScroller:bPreview_clicked(QApplication *app)
{
...
...
...
}

It doesn't give any comile time error but when I ran, it gives the following error and show the dialog.........

Object::connect: No such slot dlgTextScroller:bPreview_clicked(app)
Object::connect: (sender name: 'pbPreview')
Object::connect: (receiver name: 'dlgTextScroller')

Thanks in advance........!