PayPal get params after success returned - paypal

Question

I am currently implement PayPal into a form for articles subscription, below codes are run fine to direct to paypal web screen and process the transaction.
HOW if I want to get back certain params after transaction has successfully made? I tried echo $_REQUEST['custom'], $_REQUEST['email'], $_REQUEST['a3'] and $_REQUEST['p3'] after redirect from paypal back to returned url, BUT only $_REQUEST['custom'] is display, how can I get these params back for further proccess?
<form action="https://www.sandbox.paypal.com/cgi-bin/webscr" method="post">
<input type="hidden" name="cmd" value="_xclick-subscriptions">
<input type="hidden" name="business" value="someone_1360103868_biz#sitename.com">
<input type="hidden" name="email" value="<?php echo $BuyerEmail ?>">
<input type="hidden" name="item_name" value="<?php echo $ProdDesc ?>">
<input type="hidden" name="item_number" value="1">
<input type="hidden" name="no_shipping" value="1">
<input type="hidden" name="rm" value="2">
<input type="hidden" name="return" value="http://sitename.com/return.php?msg=Transaction+Complete">
<input type="hidden" name="cancel_return" value="http://sitename.com/return.php?msg=Transaction+Canceled">
<input type="hidden" name="notify_url" value="http://sitename.com/notify.php">
<input type="hidden" name="no_note" value="1">
<input type="hidden" name="currency_code" value="<?php echo $Currency ?>">
<input type="hidden" name="lc" value="US">
<input type="hidden" name="custom" value="<?php echo $RefNo ?>">
<input type="hidden" name="a3" value="<?php echo $Amount ?>">
<input type="hidden" name="p3" value="<?php echo $Duration ?>">
<input type="hidden" name="t3" value="M">
<input type="hidden" name="src" value="1">
<input type="hidden" name="sra" value="1">
<input type="submit" name="Submit" value="Pay now">
</form>

Answer 1

one way i have found:
try to insert this field into your generated form code:
<input type='hidden' name='rm' value='2'>
rm means return method;
2 means (post)
Than after user purchases and returns to your site url, then that url gets the POST parameters as well
p.s. if using php, try to insert var_dumy($_POST); in your return url(script),then make a test purchase and when you return back to your site you will see what variables are got on your url.

Answer 2

Trying to get back the information is not necessary if you record them on the way out, ie: before submitting to Paypal. For example it's a good idea to record all attempts so that you can follow up on failed transactions, ie: users having card problems, bugs in your code, etc.
If you are using a "good" shopping cart this will already be included. So when someone completes and submits an order form, your shopping cart adds the record and generates a new order number (ID number). The form submitting to Paypal can then include that ID number, so all that you need to retrieve after a successful transaction is that ID number and then you can programmatically update the order as paid and provide a printable receipt online that is populated from your database table.
To do this all you need to do is retrieve Request("item_number")

Answer 3

How are you wanting to return the information to your site. Are you wanting it returned to the return page on your site so that you can display it to your buyer, or are you just wanting it returned to your system to update a database. If you are wanting the mbuyer to see this on the return page, you would want to use either the return method where you use the variable "rm" and pass over the return URL in your button code. You can use a POST for this method, or you can use PDT and this will be a GET method. PDT will also allow you to validate the data against the PayPal. Then there is IPN, which will not be desplayed to the buyer. This would be used for udpating your database. See my post I made here as well, as this may have some more useful information.