function display_menu(obj){
	var el = document.getElementById("fils"+obj);
	if(el.style.display != "block"){
		el.style.display = "block";	
		document.getElementById("menu"+obj).className='lien_menu_actif';
	}else{
		el.style.display = "none";
		
		document.getElementById("menu"+obj).className='lien_menu';
		
	}
}