function MasquerZone(zoneAMasquer, sender)
{	
	if(document.getElementById(zoneAMasquer).style.visibility == "visible")
	{
		document.getElementById(zoneAMasquer).style.visibility = "hidden";
		document.getElementById(zoneAMasquer).style.display = "none";
		//change le texte du lien
		sender.innerHTML = String.fromCharCode(9658) + " ";
	}
	else
	{
		document.getElementById(zoneAMasquer).style.visibility = "visible";
		document.getElementById(zoneAMasquer).style.display = "block";
		//change le texte du lien
		sender.innerHTML = String.fromCharCode(9660) + " ";
	}
}