Creating unsubscribe button for supporter

Can anybody guide me on creating a Cancel Subscription button to place on the supporter_paypal_gateway.php page. I'm wondering if the following code would work:

<form action="https://www.paypal.com/cgi-bin/webscr" method="post">
<input type="hidden" name="cmd" value="_subscr-find">
<input type="hidden" name="business" value="blah">
<input type="hidden" name="receiver_email" value="' . get_site_option( "supporter_paypal_email" ) . '">
<input type="hidden" name="alias" value="' . get_site_option( "supporter_paypal_email" ) . '">
<input type="hidden" name="custom" value="2">
<input type="hidden" name="return" value="' . $blog_url . 'wp-admin/supporter.php?updated=canceled&updatedmsg=' . urlencode(__('Subscription Canceled!', 'supporter')) . '">>
<input type="image" src="https://www.paypal.com/images/cancel_subscribe_gen.gif" border="0" name="submit" alt="Make payments with PayPal - it's fast, free and secure!">
<input type="hidden" name="txn_type" value="subscr_cancel">
<input type="hidden" name="recurring" value="1">
<input type="hidden" name="reattempt" value="1"> </form>

Would appreciate it if someone offer some guidance. I would like the button to appear above the list of subscription plans.