private void editButton_Click(object sender, RoutedEventArgs e)
        {
            if (String.IsNullOrWhiteSpace(this.descText.Text)) {
                this.errorDesc.Visibility = Visibility.Visible;
                return;
            }

            int prize = helperFunctions.inclVAT(int.Parse(this.exBTWEuros.Text) * 100 + int.Parse(this.exBTWCents.Text));
            string old = String.Format(
                "Omschrijving: " + Environment.NewLine + "  {0} => {1}" + Environment.NewLine +
                "Prijs: " + Environment.NewLine + " {2} => {3} ",
                this.selectedProduct.Description, this.descText.Text,
                this.selectedProduct.prizeInclString, helperFunctions.prizeToString(prize));

            string dialogString = "Weet u zeker dat u dit product wilt aanpassen? " +
                Environment.NewLine + old;

            dialogYesNo dialog = new dialogYesNo("Bevestig", dialogString);
            dialog.ShowDialog();

            if (dialog.DialogResult.HasValue && dialog.DialogResult.Value) {
                this.dbhandler.updateProduct(this.selectedProduct.Id, this.descText.Text, prize);
                this.searchButton.RaiseEvent(new RoutedEventArgs(ButtonBase.ClickEvent));
            }
        }
        private void Button_Click(object sender, RoutedEventArgs e)
        {
            dialogYesNo dialog = new dialogYesNo("Bevestig", "Weet u zeker dat u deze opdracht wilt afsluiten?");
            dialog.ShowDialog();

            if (dialog.DialogResult.HasValue && dialog.DialogResult.Value){
                _mainWindow.SetPage(previousPage);
            }
        }