> On Nov 3, 2016, at 8:39 PM, Amin Aghabeiki <amin.aghabeiki at gmail.com> wrote: > > Hi John > > I plane to change check box for calendar to combo box but its really complicated > there is any guide to add combo box in preference? > Amin, No, I've never worked with the preferences dialog. Perhaps Geert can offer some help. Regards, John Ralls