Take checkbox values with javascript and view database data

Question

I’m making a shopping cart in PHP. I have two checkbox (Fetch at the counter and Delivery) and need that at the moment the user click on the checkbox Delivery the value of the delivery fee from the Bank is calculated with the total order.

My code:

      <form action"conteudo.php" name="frm" method="GET">
            <span class="servicos"><input id="bus"type="radio" name="rad" value="1">             Buscar no balcão<br>
        </span>
            <span class="servicos"><input id="bus"type="radio"name="rad" value"2"> Entrega</span>
                    </form>

    `<table width="310" border="1">
                      <thead>
                        <tr>
                          <td>Excluir</td>
                          <td>Qtde</td>
                          <td>Produto</td>
                          <td>Valor</td>       
                        </tr>
                        <br>
                      </thead>
                      <tbody>
                           <?php
                          foreach ($_SESSION['carrinho'] as $id => $qtde) {
                            $sql = "SELECT * FROM produto WHERE ID_PRODUTO = '$id'";
                            $end = mysqli_query($con,$sql);
                            while($resu = mysqli_fetch_assoc($end)){

                            $nome  = $resu['NOME_PRO'];
                            $preco = FormataValor($resu['PRECO_P']);
                            $sub   = $resu['PRECO_P'] * $qtde;
                            $total += $sub ;

                            <tr>
                              <td><a href="?acao=del&id='.$id.'">&#10148;</a></td>
                              <td>'.$qtde.'</td>
                              <td>'.$nome.'</td>
                              <td>R$'.$preco.'</td>
                            <tr>  
                              <td colspan="4"></td>
                            </tr>
                            <tr>  
                              <td colspan="4"></td>
                            </tr>';
                               }
                           }

                          ?> 

                     </tbody>

                     <tfoot>
                        </form>
                        <tr>  
                            <td colspan="4"></td>
                            </tr>
                            <tr>  
                            <td colspan="4"></td>
                            </tr>  
                        <tr>  
                          <td colspan="3">SubTotal</td>
                          <td>R$<?php echo FormataValor($total);?></td>
                        </tr>
                        <tr>  
                          <td colspan="3">Taxa Entrega</td>
                          <td><?php 
                          if(isset($_GET['rad'])){
                            echo $resu['TAXA_ENTREGA'];}?></td>
                        </tr>
                        <tr>  
                          <td colspan="3">Total</td>
                          <td>R$<?php echo FormataValor($total) ;?></td>
                        </tr>
                    </tfoot>
                  </table>
                  <a href="index.php">Continuar Comprando</a`>