@array1=qw( 1 2 3 4);
$aref = \@array1;
@array2=qw(5 6 7 8);
$aref=\@array2;

$# of $aref is now 1

print $aref[1][2]; # this will print "7"

 here is the example CGI script i dont understand the methods useage .  this lesson is in makeing a cgi guestbook.

#! /usr/bin/perl -w

use 5.004;
use strict;
use CGI qw(:standard);
use Fcntl qw(:flock);

sub bail {
        my $error = "@_";
        print h1("Enexpected Error"), p($error), end_html;
        die $error;
}

my (
        $CHATNAME,
        $MAXSAVE,
        $TITLE,
        $cur,
        @entries,
        $entry
);

$TITLE = "Simple Guestbook";
$CHATNAME= "chatfile";
$MAXSAVE = 10;

print header, start_html($TITLE), h1($TITLE);

$cur = CGI->new();
if ($cur->param("message")) {
        $cur->param("date", scalar localtime);
        @entries=($cur);
}

open(CHANDLE, "+< $CHATNAME") || bail("cannot open $CHATNAME: $!");

flock(CHANDLE, LOCK_EX) || bail("cannot flock $CHATNAME: $!");

while (!eof(CHANDLE) && @entries < $MAXSAVE) {
        $entry = CGI->new(\*CHANDLE);
        push @entries, $entry;
}

seek(CHANDLE, 0, 0) || bail("cannot rewind $CHATNAME: $!");
foreach $entry (@entries) {
        $entry->save(\*CHANDLE);
}
truncate(CHANDLE, tell(CHANDLE)) || bail ("cannot truncate $CHATNAME: $!");
close(CHANDLE) || bail ("cannot close $CHATNAME: $!");

print hr, start_form;
print p("Name:", $cur->textfield(
        -NAME => "message"));
print p("Message:", $cur->textfield(
        -NAME => "message",
        -OVERRIDE => 1,
        -SIZE => 50));
print p(submit("send"), reset("clear"));
print end_form, hr;

print h2("Prior Messages");
foreach $entry (@entries) {
        printf("%s [%s]: %s",
        $entry->param("date"),
        $entry->param("name"),
        $entry->param("message"));
        print br();
}
print end_html;