my $html = HTML::TagParser->new($line);
my @elem = $html->getElementsByClassName($class);

##</code><code>##

my $html = HTML::TagParser->new($line);
my $body = $html->getElementById($id);
my @elem = $body->getElementsByClassName($class);

##</code><code>##

my $html = HTML::TagParser->new($line);
my $body = $html->getElementById($id);
$body = $body->subTree(); # $body is now a new HTML::TagParser object
my @elem = $body->getElementsByClassName($class);