center oracle forms 6i

declare
wind_x number;
wind_y number;
wind_w number;
wind_h number;
BEGIN
SET_WINDOW_PROPERTY(FORMS_MDI_WINDOW,WINDOW_STATE,MAXIMIZE);
SET_WINDOW_PROPERTY(FORMS_MDI_WINDOW,TITLE, 'ADC ltd     Sales Management System');
wind_w:=get_window_property(FORMS_MDI_WINDOW,WIDTH);
wind_h:=get_window_property(FORMS_MDI_WINDOW,height);
wind_x:=get_window_property(FORMS_MDI_WINDOW,x_pos);
wind_y:=get_window_property(FORMS_MDI_WINDOW,y_pos);
SET_WINDOW_PROPERTY('WINDOW1',X_POS,(wind_w-get_window_property('WINDOW1',width))/2);
SET_WINDOW_PROPERTY('WINDOW1',Y_POS,(wind_h-get_window_property('WINDOW1',height))/2);

END;