More than one search box - html validation error

[voldemort]

I am setting up a site and the client wants to have more than one search box.

A main search box for the whole site and a second search box to search just the what's on (calendar) section - but it could be anything.

The options in setting up the search function are great and the functionality is fine.  However the page doesn't validate for html for the simple reason that the search box uses a div id that should only be used once per page:

<input type="text" id="cntnt01searchinput" name="cntnt01searchinput" size="20"

The actual html page is here: http://www.discover-poitou-charentes.com/index.php

I can't see a way of getting round this - can anyone help?