silverstripe-cms/templates/SilverStripe/CMS/Search/Includes/SearchForm.ss

<form $FormAttributes>
	<% if $Message %>
	<p id="{$FormName}_error" class="alert $AlertType">$Message</p>
	<% else %>
	<p id="{$FormName}_error" class="alert $AlertType" style="display: none"></p>
	<% end_if %>
	<fieldset>
		<% loop $Fields %>
		$FieldHolder
		<% end_loop %>
		<% loop $Actions %>
		$Field
		<% end_loop %>
	</fieldset>
</form>