PHP simple Paypal IPN

To setup a quick Paypal IPN

This quicky uses the code from
http://code.google.com/p/paypal-ipn-class-php/

Download code; unzip; place in site;

Next create your Paypal Button form. Make sure it Posts to paypal.php.
Use paypal.php?sandbox=1 to test in the sandbox

<form action="paypal.php?sandbox=1" method="post">
<input type="hidden" name="cmd" value="_xclick">
<input type="hidden" name="business" value="PAYPAL EMAIL ADDRESS">
<input type="hidden" name="lc" value="US">
<input type="hidden" name="item_name" value="Stuff">
<input type="hidden" name="item_number" value="123">
<input type="hidden" name="amount" value="2.99">
<input type="hidden" name="currency_code" value="USD">
<input type="hidden" name="button_subtype" value="services">
<input type="hidden" name="no_note" value="1">
<input type="hidden" name="no_shipping" value="1"> 
<input type="image" src="https://www.paypalobjects.com/en_US/i/btn/btn_buynowCC_LG.gif" border="0" name="submit" alt="PayPal - The safer, easier way to pay online!">
<img alt="" border="0" src="https://www.paypalobjects.com/en_US/i/scr/pixel.gif" width="1" height="1">
</form>

Next make sure you change the 2 settings for the emails and ADD the line for the SMTP server

 define('EMAIL_ADD', 'PAYPALEMAIL'); // For system notification.
 define('PAYPAL_EMAIL_ADD', 'PAYPALEMAIL');
ini_set("SMTP", "mail.MAILSERVER.com");

Then down on line 96ish add the fields from your specific form to look like

$p->add_field('business', PAYPAL_EMAIL_ADD); //don't need add this item. if your set the $p -> paypal_mail.
            $p->add_field('return', $this_script.'?action=success');
            $p->add_field('cancel_return', $this_script.'?action=cancel');
            $p->add_field('notify_url', $this_script.'?action=ipn');
            $p->add_field('item_name', $_POST['item_name']);
            $p->add_field('item_number', $_POST['item_number']);
            $p->add_field('lc', $_POST['lc']);
            $p->add_field('amount', $_POST['amount']);
            $p->add_field('cmd', '_xclick');
            $p->add_field('rm', '2');    // Return method = POST