public function get_transaction_url($order)
{
if ($this->testmode) {
$this->view_transaction_url = 'https://www.sandbox.paypal.com/cgi-bin/webscr?cmd=_view-a-trans&id=%s';
} else {
$this->view_transaction_url = 'https://www.paypal.com/cgi-bin/webscr?cmd=_view-a-trans&id=%s';
}
return parent::get_transaction_url($order);
}