PayPal付款后返回商家网站

我的网站上有一个PHP表单，当用户单击提交时，他们会被重定向到预订确认页面。在这一点上，我已经建立了一个贝宝连接（沙盒）如下；

<form action="https://www.sandbox.paypal.com/cgi-bin/webscr" method="post">
        <input type="hidden" name="cmd" value="_cart">
        <input type="hidden" name="business" value="youremail@email.com">
        <input type="hidden" name="currency_code" value="EUR">
        <input type="hidden" name="upload" value="1">
        <b>First name:</b><span style="padding-left:5em;"></span>
        <input type="text" name="first_name" style="width:20em;">
        <br><br>
        <b>Last name:</b><span style="padding-left:5.1em;"></span>
        <input type="text" name="last_name" style="width:20em;">
        <br>
        <b>Email Address:</b><span style="padding-left:3.35em;"></span>
        <input type="text" name="email" style="width:20em;">
        <input type="hidden" name="custom" value="<?php echo $randomString ?>"/>
        <input type="hidden" name="return" value="http://www.example.com/thank-you/">
        <input type="hidden" name="notify_url" value="https://www.example.com/my_ipn.php">
        <input type="hidden" name="rm" value="2"> 
        <?php 
        if (($Adults > 0) && ($Students > 0) && ($Children > 0))
        {
            echo "<input type='hidden' name='item_name_1' value='" . $selectroute ." (Adult - " . $ticket .")'>";
            echo "<input type='hidden' name='amount_1' value='15'>";
            echo "<input type='hidden' name='quantity_1' value='" . $Adults . "'>";
            echo "<input type='hidden' name='item_name_2' value='" . $selectroute ." (Student - " . $ticket .")'>";
            echo "<input type='hidden' name='amount_2' value='15'>";
            echo "<input type='hidden' name='quantity_2' value='" . $Students . "'>";
            echo "<input type='hidden' name='item_name_3' value='" . $selectroute ." (Child - " . $ticket .")'>";
            echo "<input type='hidden' name='amount_3' value='15'>";
            echo "<input type='hidden' name='quantity_3' value='" . $Children . "'>";
        }
        elseif (($Adults > 0) && ($Students > 0))
        {
            echo "<input type='hidden' name='item_name_1' value='" . $selectroute ." (Adult - " . $ticket .")'>";
            echo "<input type='hidden' name='amount_1' value='15'>";
            echo "<input type='hidden' name='quantity_1' value='" . $Adults . "'>";
            echo "<input type='hidden' name='item_name_2' value='" . $selectroute ." (Student - " . $ticket .")'>";
            echo "<input type='hidden' name='amount_2' value='15'>";
            echo "<input type='hidden' name='quantity_2' value='" . $Students . "'>";
        }
        elseif (($Students > 0) && ($Children > 0))
        {
            echo "<input type='hidden' name='item_name_1' value='" . $selectroute ." (Student - " . $ticket .")'>";
            echo "<input type='hidden' name='amount_1' value='15'>";
            echo "<input type='hidden' name='quantity_1' value='" . $Students . "'>";
            echo "<input type='hidden' name='item_name_2' value='" . $selectroute ." (Child - " . $ticket .")'>";
            echo "<input type='hidden' name='amount_2' value='15'>";
            echo "<input type='hidden' name='quantity_2' value='" . $Children . "'>";
        }
        elseif (($Adults > 0) && ($Children > 0))
        {
            echo "<input type='hidden' name='item_name_1' value='" . $selectroute ." (Adult - " . $ticket .")'>";
            echo "<input type='hidden' name='amount_1' value='15'>";
            echo "<input type='hidden' name='quantity_1' value='" . $Adults . "'>";
            echo "<input type='hidden' name='item_name_2' value='" . $selectroute ." (Child - " . $ticket .")'>";
            echo "<input type='hidden' name='amount_2' value='15'>";
            echo "<input type='hidden' name='quantity_2' value='" . $Children . "'>";
        }
        elseif ($Adults > 0)
        {
            echo "<input type='hidden' name='item_name_1' value='" . $selectroute ." (Adult - " . $ticket .")'>";
            echo "<input type='hidden' name='amount_1' value='15'>";
            echo "<input type='hidden' name='quantity_1' value='" . $Adults . "'>";
        }
        elseif ($Students > 0)
        {
            echo "<input type='hidden' name='item_name_1' value='" . $selectroute ." (Student - " . $ticket .")'>";
            echo "<input type='hidden' name='amount_1' value='15'>";
            echo "<input type='hidden' name='quantity_1' value='" . $Students . "'>";
        }
        elseif ($Children > 0)
        {
            echo "<input type='hidden' name='item_name_1' value='" . $selectroute ." (Child - " . $ticket .")'>";
            echo "<input type='hidden' name='amount_1' value='15'>";
            echo "<input type='hidden' name='quantity_1' value='" . $Children . "'>";
        }
        ?>
        <input type="image" src="https://www.paypalobjects.com/webstatic/en_US/btn/btn_paynow_cc_144x47.png" border="0" name="submit" alt="PayPal - The safer, easier way to pay online!" style="position:relative; top: 8em; padding-left:15em;">
        <img alt="" border="0" src="https://www.sandbox.paypal.com/en_US/i/scr/pixel.gif" width="1" height="1">
    </form>

如上所述，上面的表单采用用户在PHP预订表单上输入的值，并将其显示在Paypal的订单摘要部分。然后我可以作为买家登录并付款。然后我想回到http://www.example.com/thank-you/但我却登录了一个PayPal页面，上面写着交易ID和付款已处理的确认。

如何返回商家网站上的感谢页面，而不是PayPal网站上的？

我打开了"自动返回"，并设置了返回URL。正如您在上面看到的，我已经指定了return和rm变量，但没有运气。

如有任何建议，我们将不胜感激。