smarthost

I try to add this code: $certificate="file:///data/web/virtuals/dev.smarthost.cz/secure/smarthost.crt"; $info = array( 'Name' => 'TCPDF', 'Location' => 'Office', 'Reason' => 'Testing TCPDF', 'ContactInfo' => 'http://www.tcpdf.org', ); $pdf->setSignature($certificate,$certificate,'','',2,$info); to invoicepdf.tpl in my template direcory, but document is still unsigned. What I do wrong?

I'm making custom payment gateway. How can I mark payment invoice as payed? I understand, that i must do it in callback php file named by my payment gateway file.But I don't know how when the file is executed, or how can I this file activate to mark payment as payed.