#!/usr/bin/perl -wT
#index.pl
use CGI qw/ :all /;
my $fs = param("fs") || 0; # frameset
my $fr = param("fr") || 0; # frame

## only numbers are acceptable

$fs =~ s/\D//g;
$fr =~ s/\D//g;

$fs ||= 0; # if they weren't defined, or were gibberish
$fr ||= 0; # they best be 0

$|=1; # unbuffer

print  header(-type => 'text/html', # cache only for five minutes
              -expires => '+5m'  ), # you clients that cache

if($fs == 1)
{
    &generate_frameset1();
}
elsif($fs ==2)
{
    if($fr == 2)
    {
        &generate_frame2();
    }
    elsif($fr == 3)
    {
        &generate_frame3()
    }
    else
    {
        &generate_frameset1();
    }
}
else
{
    &generate_frameset_all();
}
### ... the actual subroutines below
### index.pl writes something like
<frameset 1>
    <frame src ="index.pl?fs=1;fr=1;">

    <frameset 2>
        <frame src ="index.pl?fs=2;fr=3;">
        <frame src ="index.pl?fs=2;fr=3;">
    </frameset>
</frameset>