image functions => text alignment

Hi all, I'm writing a script that generate invoices in a PNG files. My problem is that I have to write the numbers aligned to the right. I'm using the funciotn ImageTTFText and it haven't a parm that tells the alignment. I looked at the IMAGE functions list in www.php.net but I didn't found nothing about the alignment. Does anyone know if there's a function or a parameter to write with TTF fonts aligned to the RIGHT? Thank, Fabio www.kel666.it