use strict;
use warnings;
use CGI;
use constant PICS_PER_PAGE => 20;
my @pics = ('pic1.jpg', 'pic2.jpg');
my $cgi = new CGI;
my $start = $cgi->param('start') || 0;
foreach($start..($start + PICS_PER_PAGE - 1)){
last unless(defined $pics[$_]);
print qq();
}
my $newstart = $start + PICS_PER_PAGE;
print qq();