private void btnEdit_Click(object sender, RoutedEventArgs e)
        {
            ServisAddEdit frmPrijavaAddEdit = new ServisAddEdit(CurrentServis);

            frmPrijavaAddEdit.ServisCreated += new ServisHandler(Refresh);
            frmPrijavaAddEdit.Show();
        }
        private void btnDodaj_Click(object sender, RoutedEventArgs e)
        {
            ServisAddEdit frmServisAddEdit = new ServisAddEdit(new Servis()
            {
                Datum = DateTime.Now
            });

            frmServisAddEdit.ServisCreated += new ServisHandler(Refresh);
            frmServisAddEdit.Show();
        }