var prevnav = null;
var prevnavsub = null;

function shownav(n) {
	if (prevnav) { 
		document.getElementById("submenu"+prevnav).style.display = "none";
	}
	if (prevnavsub && document.getElementById("subsub"+prevnavsub)!=null) {
		document.getElementById("subsub"+prevnavsub).style.display = "none";
		document.getElementById("subtriangle"+prevnavsub).style.display = "none";
	}
	document.getElementById("submenu"+n).style.display = "block";
	
	document.getElementById("closemenu").style.zIndex = 300;
	
	prevnav = n;
}