foreach (@$diff) {
        if (m/^\@\@(.*)\@\@$/) {
            $str .= qq{<p id="rev">$1</p>};
        }
        elsif (m/^\-(.*)$/) {
            push @$old, $1;
        }
        elsif (m/^\+(.*)$/) {
            push @$new, $1;
        }
        else {
            my $tst = $_;
            $str .= getHTMLDiff($old, $new) . $tst;
            undef $old;
            undef $new;
        }
    }
    $str .= getHTMLDiff($old, $new);