use strict;
use warnings;
use diagnostics;
use HTTP::Module;
use Some::Module;

my ($dbuser,           # database username
    $dbpass,           # password for db
    $dbhost,           # host for the database
    $dbport,           # db connection port
    $dbname,           # name of the database used
    $dbh,              # DBI handle
    $foo,              # for foo
    $bar,              # for bar
    $baz,              # for baz
    %quux,             # quux hash
    );

$dbuser = 'nobody';
$dbpass = 'NobodyPassword';
$dbport = '3306';
$dbhost = 'localhost';

$dbh    = DBI->connect('DBI:mysql:$dbname:$dbhost:$dbport',
                        $dbuser, $dbpass, {RaiseError => 1});

&init();               # initialize basic environment
&print_header();       # CGI.pm basic header/content-type
&top_of_page();        # print top menubars, logos, etc.
&middle_of_page();     # main content, DBI results, etc.
&bottom_of_page();     # bottom cleanup HTML, copyright, etc.
&end_content();        # finish HTML, close handles
 
if (!$vars{action} || $vars{action} eq "home") {
        # if the user hits the main page, or clicks 'home'
        # from the menubar, show the basic HTML content, no
        # sections
        &left_content();
        &right_content();
}
 
sub init {
        # ...
}
 
sub print_header {
        my $query      = new CGI;
        %vars          = $query->Vars();
        # ...
}

sub top_of_page {
        # ...
}

sub middle_of_page {
        # ...
        $dbh  = DBI->connect(..);
        # prepare, execute and print query results
        # wrapped in HTML elements
}

sub left_content {
        # Only shown when the user is on the main page 
        # (no $vars{action} parsed) or they have 
        # selected 'home' from the HTML menu displayed. 
        # ... 
}
 
sub right_content {
        # ..compliment to the 'left_content' sub above
        # ...
}

sub bottom_of_page {
        # ...
}

sub end_content {
        # ...
}

##</code><code>##

sub init {
        use strict;
        use warnings;
        use diagnostics;
        use HTTP::Module;
        use Some::Module;
}

sub print_header { 
        my $query      = new CGI;
        %vars          = $query->Vars();
        # ...
}

sub top_of_page {
        # ...

}

sub middle_of_page {
        # ...
        my ($dbuser,           # database username
            $dbpass,           # password for db 
            $dbhost,           # host for the database
            $dbport,           # db connection port
            $dbname,           # name of the database used
            $dbh,              # DBI handle
           );

            $dbuser = 'nobody';
            $dbpass = 'NobodyPassword';
            $dbport = '3306';
            $dbhost = 'localhost';

            $dbh    = DBI->connect('DBI:mysql:$dbname:$dbhost:$dbport',
                        $dbuser, $dbpass, {RaiseError => 1});
}

sub left_content {
        if (!$vars{action} || $vars{action} eq "home") {
                # print the generic left content here
        } 
        # ...
}

sub right_content {
        if (!$vars{action} || $vars{action} eq "home") {
                # print the generic right content here
        }
        # ...
}

sub bottom_of_page {
        # ...
}

sub end_content {
        # ...
}