Regexp for xhtml compliant matching

Hi all, I've come to the end of my rope looking for a nice regexp that matches xhtml compliant code. I'm trying to match the content of the body tag, so that HTML_Page can properly parse a document. Don't know exactly how to do it. That is, it's easy to match the following: <html> <head> <title /> </head> <body> <p>some content</p> </body> </html> But... add an embeded html document, and it's not so easy: <html> <head> <title /> </head> <body> <p>some content</p> <!-- embedded documents are possible, --> <!-- though still rather uncommon --> <html> <head><title /></head> <body><p>some content</p></body> </html> </body> </html> Any ideas? TIA, Klaus