Some problems with jQuery UI

Hi to every:
I was getting some problems using jQuery UI Highlight and Error box
fields. The live example is at this address:
http://www.jose-couto.com/jcgoogle/index.php/search/index/data/t
As you may notice here a message could be appear but instead nothing is
showing. Why? What I'm doing wrong?
Cheers and thanks in advance
--
ReynierPM
--