function rendreMenuInvisible(){		
		document.getElementById('menu-principal').style.zIndex = '2';
		document.getElementById('menu-fixed').style.zIndex = '3';	
}

function rendreMenuVisible(){
	setTimeout("delai()", 700);		
}

function delai(){
	document.getElementById('menu-principal').style.zIndex = '3';
	document.getElementById('menu-fixed').style.zIndex = '2';
}