I dunno..I just put it in and it works - I'll show you
HTML Code:
<form action="search.php" method="post">
<input type="text" name="query" class="query" size="30" />
<input type="image" class="search-btn" src="assets/search_btn.gif" alt="search" title="search" />
</form>
That's what I use and it works...