var onOff = "hide";
var onOffIE = "hidden";

function toggleMenu(arg) {

	if (document.layers) { // Condition pour Netscape 4.x
		var onOff = document.layers[arg].visibility
		for (i=1; i<=5; i++) {
			document.layers["menu" + i].visibility = "hide"
		}
		if (onOff == "show") {
			document.layers[arg].visibility = "hide";
		}
		else if (onOff == "hide") {
			document.layers[arg].visibility = "show";
		}
	}
	else if (document.all) {  // Condition pour Explorer =< 5.0
		var onOffIE =document.all[arg].style.visibility;
		for (i=1; i<=5; i++) {
			document.all["menu" + i].style.visibility = "hidden"
		}
		switch (onOffIE) {
			case "visible" :
				document.all[arg].style.visibility = "hidden";
				break;
			case "hidden" :
				document.all[arg].style.visibility = "visible";
				break;
			case "" :
				document.all[arg].style.visibility = "visible";
				break;
		}
	}
	else {// Condition pour Netscape 6.x & Explorer >= 5.0.1
		var onOffNS = document.getElementById(arg).style.visibility
		document.getElementById("menu1").style.visibility = "hidden";
		document.getElementById("menu2").style.visibility = "hidden";
		document.getElementById("menu3").style.visibility = "hidden";
		document.getElementById("menu4").style.visibility = "hidden";
		document.getElementById("menu5").style.visibility = "hidden";
		switch (onOffNS) {
			case "visible" :
				document.getElementById(arg).style.visibility = "hidden";
				break;
			case "hidden" :
				document.getElementById(arg).style.visibility = "visible";
				break;
			case "" :
				document.getElementById(arg).style.visibility = "visible";
				break;
		}
	}
}