title: How can I test the markup validity of a string (webpage) in .Net?
body: <p>I've written a VB.Net page to browse my site. It stores the HttpWebResponse in a string. How can I validate the markup validity of the page in .Net? - something similar to W3's validate by direct input option. I'm looking for something that can identify the DOCTYPE, validate it yes or no, and return a list of failures I can display.</p>