function SwitchMenu(obj){
	if(document.getElementById){
	var el = document.getElementById(obj);
	var ar = document.getElementById("masterdiv").getElementsByTagName("span"); 
		if(el.style.display != "block"){ 
			for (var i=0; i<ar.length; i++){
				if (ar[i].className=="submenu"){
					ar[i].style.display = "none";
				}
				if (ar[i].id == obj)
				{
					var chaine = new String("menu_"+obj);
					var imgscr = document.images[chaine].src;
					imgscr = imgscr.replace("bas.gif","haut.gif");
					document.images[chaine].src = imgscr;
				}
				else{
					var imgscr = document.images["menu_"+ar[i].id].src;
					imgscr = imgscr.replace("haut.gif","bas.gif");
					document.images["menu_"+ar[i].id].src = imgscr;	
				}
			}
			el.style.display = "block";
		}else{
			var imgscr = document.images["menu_"+obj].src;
			imgscr = imgscr.replace("haut.gif","bas.gif");
			document.images["menu_"+obj].src = imgscr;			
			el.style.display = "none";
		}
	}
}