my $cookie = $ENV{'HTTP_COOKIE'}; # if you wanna do this like that.
@all = split(/\;/, $cookie);
foreach (@all) {
    ($var, $value) = split(/=/);
    $values{$var} = $value;
}

##</code><code>##

my $username = $values{'username'};
my $password = $values{'password'};
# now do whatever you want with them.