html Code

                     <tr>
                        <th colspan="6" style="text-align: left;">
                            <a class="btn btn-primary pull-right director_add"> </a>
                        </th>
                    </tr>
                <tbody class="director_form">
                    <tr>
                        <td class="tdleft" width="10%">:</td>
                        <td width="20%">
                            <input  type="text" name="director_cn_name" id="director_cn_name" />
                            <i class="dealdone" aria-hidden="true">*</i>
                        </td>
                    </tr>
                    <tr>
                        <td class="tdleft" width="10%">:</td>
                        <td width="20%">
                            <select id="director_payment_method" name="director_payment_method">
                                <option value="1"></option>
                                <option value="2"></option>
                            </select>
                            <i class="dealdone" aria-hidden="true">*</i>
                        </td>
                    </tr>
                    <tr>
                        <td class="tdleft" width="10%">:</td>
                        <td colspan="2" width="35%">
                            <input  type="radio" name="director_tax" id="director_tax1"  class="director_tax"  value="1"/>  
                            <input  type="radio" name="director_tax" id="director_tax"   class="director_tax"  value="0" checked/>  
                        </td>
                        <td class="tdleft director_tax_amount" width="10%" style="display: none;">:</td>
                        <td class="director_tax_amount" colspan="2" width="35%" style="display: none;">
                            <input type="text" name="director_tax_amount" id="director_tax_amount"/>
                            <i class="required" aria-hidden="true">*</i>
                        </td>
                    </tr>
                    </tbody>

I click the button to add a director and execute:

        $(".director_add").click(function () {
            $(".director_form").after($(".director_form").html());
        });

execute when choosing whether or not to include tax:

    $(".director_tax").on("change", function(){
            if ($(this).val() == "1") {
                $(".director_tax_amount").show();
            } else {
                $(".director_tax_amount").hide();
            }
        });

problems encountered:

1:id is director_tax is 0. There are no default values in dynamically generated elements?
2: when the tax value is 1, this time does not take effect in dynamically generated elements?

what is the reason for this? ask the Great God for an answer. Thank you.