Re: what is wrong?

Cristina's right, of course!

Also keep in mind that a valid xhtml website is an investment in the
future. I imagine it won't be too long until search engines start using
validation as a partial basis for ranking. The reason behind that is
that a valid web page can easily be split into blocks and processed
with a block level analysis, allowing the search engines to find and
extract the relevant information much easier.

A valid web page also helps to make sure that the site can be viewed on
a number of different systems, if they're using ie, firefox, opera, etc
-- even on browsers for the visual impaired or for mobile phones. If
the page is not valid, sometimes it's just luck that it displays
properly at all (and you never know when that luck will dry up).

John