function show(args){
		var id = arguments[0];
		var idNav = id + "Nav";
		// if more than 1 arg: hide these first
		if(arguments[1]){
			for(var i=1; i<arguments.length; i++){
				var idNavs = arguments[i] + "Nav";
				document.getElementById(arguments[i]).style.display = "none";
					if(document.getElementById(idNavs) != null)
					document.getElementById(idNavs).innerHTML= "+";
			}
		}
		if (document.getElementById(id).style.display == "none"){
			document.getElementById(id).style.display = "block";
			document.getElementById(idNav).innerHTML= "-";
		}else{
			document.getElementById(id).style.display = "none";
			document.getElementById(idNav).innerHTML= "+";
		}
	}