Search form - by mkep - on WordPress WooCommerce support

Hello,

How can I change the text “Search for…” on the search modal window ?

Its not in the .po traduction…

<div class="modal-dialog text-center">
					<h3 class="large-h">Rechercher un produit</h3>
					<small class="mini-text">Utilisez ce formulaire pour trouver ce que vous cherchez</small>
				
					    
        
	<form method="get" class="hide-input" id="searchform" action="http://www.vente-terminal-de-paiement.com/"> 
		<div class="form-horizontal modal-form">
			<div class="form-group has-border">
				<div class="col-xs-10">
					<input type="text" id="s" name="s" onfocus="if(this.value=='Search for...')this.value=''" onblur="if(this.value=='')this.value='<strong>Search for...</strong>'" class="form-control" value="Search for...">
					<input type="hidden" value="product" name="post_type">
				</div>
			</div>
			<div class="form-group form-button">
				<button class="btn medium-btn btn-black" type="submit">Rechercher</button>
			</div>
		</div>
	</form>
	
					
				</div>

Thanks