Hi Alberto,
you've got a few mistakes in your hand-code in the Search form. Those are easy enough to fix, but the end result is probably not what you're after anyway.
so first the mistakes.
(Incidentally all of these showed up in the Console log in fireBug, so if you're not using that you definitely should.)
a) as you know you've got to make xHtml, not just html. This means all attributes must be of the form something="whatever" - the quotes are important. So add quotes to COLOR, BGCOLOR, SCROLL and so on.
b) you're calling "exit" after sending the code, but before the call to DivFooter. So the Div is being opened (DivHeader) but not closed in Div Footer.
Once you've got that working, and seen the effect, I think you'll want to change it - but let's get there first and see how you go.
cheers
Bruce