Радио бутон в страницата за плащане на opencart

Нов съм в php и opencart. но планирах да настроя своя онлайн магазин. Създавах опция за избор на слот за време за доставка в страницата за плащане в opencart. Както е показано на снимката по-долу:

И така, започнах да пиша vqmod, за да постигна това, но останах в това как да съхраня стойността в базата данни: Моят xml изглежда така:

<modification>
<id>Salutation Field Modification</id>
<version>1</version>
<vqmver>1.0.8</vqmver>
<author>maca</author>
<file name="catalog/view/theme/bigshop/template/checkout/shipping_method.tpl">
    <operation>
        <search position="before"><![CDATA[
            <p><?php echo $text_shipping_method; ?></p>
        ]]></search>
        <add><![CDATA[
            <p><?php echo $text_shipping_timeslot; ?></p>
            <table class="radio">

      <tr>
        <td colspan="3"><b><?php echo "Delivery time slot"; ?></b></td>
      </tr>
      <tr class="highlight">
        <td>
          <input type="radio" name="shipping_timeslot" value="><?php echo $ship_slot_one; ?></" id="morning?>" checked="checked"/><?php echo $ship_slot_one; ?></br>
          <input type="radio" name="shipping_timeslot" value="><?php echo $ship_slot_two; ?></" id="afternoon?>"/><?php echo $ship_slot_two; ?></br>
          <input type="radio" name="shipping_timeslot" value="><?php echo $ship_slot_three; ?></" id="evening?>"/><?php echo $ship_slot_three; ?></br>
          <input type="radio" name="shipping_timeslot" value="><?php echo $ship_slot_four; ?></" id="night?>"/><?php echo $ship_slot_four; ?></br>
        </td>
      </tr>
      <tr>
        <td colspan="3"></td>
      </tr>
      </table>
        ]]></add>
    </operation>
</file>
<file name="catalog/language/english/checkout/checkout.php">
    <operation>
        <search position="before"><![CDATA[
            $_['text_shipping_method']           = 'Please select the preferred shipping method to use on this order.';
        ]]></search>
        <add><![CDATA[
            $_['text_shipping_timeslot']           = 'Please select the preferred shipping time slot.';
            $_['ship_slot_one']           = 'Morning';
            $_['ship_slot_two']           = 'Afternoon';
            $_['ship_slot_three']           = 'Evening';
            $_['ship_slot_four']           = 'Night';
        ]]></add>
    </operation>
</file>

   <file name="catalog/controller/checkout/shipping_method.php">
       <operation>
           <search position="before"><![CDATA[
               $this->data['text_shipping_method'] = $this->language->get('text_shipping_method');
           ]]></search>
           <add><![CDATA[
               $this->data['text_shipping_timeslot'] = $this->language->get('text_shipping_timeslot');
               $this->data['ship_slot_one'] = $this->language->get('ship_slot_one');
               $this->data['ship_slot_two'] = $this->language->get('ship_slot_two');
               $this->data['ship_slot_three'] = $this->language->get('ship_slot_three');
               $this->data['ship_slot_four'] = $this->language->get('ship_slot_four');
           ]]></add>
       </operation>

   </file>

</modification>

Моля, насочете ме.