Instead of parsing some specific HTML elements with Regex, it would be better to use some general approach and parse HTML. You will be able to find some open-source parsers, for example:
http://www.majestic12.co.uk/projects/html_parser.php[
^].
It would be the best if HTML was well-formed XML which you could easily parse with any of the XML parsers which come with .NET FCL, but, unfortunately, this is not always the case.
—SA