Cacher is the code snippet organizer for pro developers

<?php
function my_search_form( $form ) {
	$form = '<form role="search" method="get" id="searchform" class="search-form" action="' . home_url( '/' ) . '" >
	<div><input type="text" value="' . get_search_query() . '" name="s" id="searchfield" placeholder="'. __( 'Rechercher sur le site' ) .'" />
	<input type="submit" id="searchsubmit" value="'. __( 'Rechercher' ) .'" />
	</div>
	</form>';

	return $form;
}

add_filter( 'get_search_form', 'my_search_form' );