Search not working

Hi all, I’m quite new to WP and enjoying the learning curve but I’ve been struggling to get the search working.

I’ve got the following code in header.php:

<div style="float:right; vertical-align:bottom;" > <?php include (TEMPLATEPATH . '/searchform.php'); ?></div>

and in searchform.php:

<form method="get" id="searchform" action="<?php bloginfo('url'); ?>/">
  <div>
    <input type="text" size="18" value=" " name="s" id="s" />
    <input type="submit" id="searchsubmit" value="Search" class="btn" />
  </div>
</form>

I’m sure I’m missing some fundamental but can’t get to the bottom of it. Any help much appreciated!