Paypal button auto-return url not overriding the default url

问题

I have enabled auto-return after a paypal customer purchase in the sandbox paypal settings. I have also specified a return url in the settings e.g. www.example.com because it was compulsory. However, I want the return URL to be dynamically set in the payment button e.g.

<form name="_xclick" action="https://www.sandbox.paypal.com/cgi-bin/webscr" method="post">
    <input type="hidden" name="cmd" value="_xclick">
    <input type="hidden" name="business" value="company@life.com">
    <input type="hidden" name="currency_code" value="GBP">
    <input type="hidden" name="item_name" value="Enquiry Estimate">
    <input type="hidden" name="amount" value="250">
    <input type="hidden" name="return" value="http://example.com/order/success?order=1654321">
    <input type="hidden" name="notify_url" value="">
    <input type="submit" value="Accept and Pay Now" />
</form>

The auto return url when the user pays with this particular button should be

http://example.com/order/success?order=1654321

instead of just example.com

Why is the URL not being overridden? Whenever a payment is made, Paypal is redirecting to example.com only.

来源：https://stackoverflow.com/questions/21464153/paypal-button-auto-return-url-not-overriding-the-default-url