function otworz(numer) 
{
 l = Math.round((screen.width-800)/2);
 t = Math.round((screen.height-536)/2);
 noweOkno = window.open('zdj.php?n='+numer, 'Device', 'left='+l+',top='+t+',width=800,height=536,status=0,toolbar=0,menubar=0,scrollbars=0,resizable=0,location=0,directories=0');
}