为成功页面添加额外自定义字段。在Paypal

Question

我需要在返回页面上添加多个额外字段。但我只能通过一个场地。我的代码是： -

 <form class="validate" id="paypalform"  method="post" action="https://www.sandbox.paypal.com/cgi-bin/webscr">
                            <h3>Amount :- $5.99</h3>

                            <p class="mc-field-group clearfix">
                               Email : <input required class="required email mce_inline_error" id="mce-EMAIL" name="custom" type="email" value="" aria-required="true" aria-invalid="true">
                            </p>

                            <input type="hidden" name="business" value="er.XXX@gmail.com">
                            <input type="hidden" name="cmd" value="_xclick">
                            <input type="hidden" name="item_name" value="Closer t">
                            <input type="hidden" name="item_number" value="1">

                            <input type="hidden" id="amount" name="amount" value="54.99">
                            <input type="hidden" name="cancel_return" value="http://website.com/aypal-notcompleted/">
                            <input name="notify_url" value="http://website.com/paypal-ipn/" type="hidden" >
                            <input type="hidden" name="no_shipping" value="1">
                            <input type="hidden" name="currency_code" value="USD">
                            <input type="hidden" name="handling" value="0">
                            <input type="hidden" name="invoice_id" value="fffff"/>

                            <div class="btn">
                                <button class="btn btn-danger" type="submit" >
                                    Paynow
                                </button>
                            </div>         
         </form> 

on success.php页面

 echo "<pre>";
   print_r($_GET);
   die;

输出： -

Array
(
    [tx] => 7KC790518W762915S
    [st] => Pending
    [amt] => 5.99
    [cc] => USD
    [cm] => asheesh9308@gmail.com
    [item_number] => 1
)

但我希望在成功页面上也可以使用invoice_id