var fc = tek;
var nc = tek;
function chnav(i) {
	if (nc == i) return;
	document.getElementById("nav" + i).className = "a" + i;
	if (nc < 5) document.getElementById("nav" + nc).className = "n" + nc;
	nc = i;
}
function chlay(i) {
	if (tek == i) return;
	if (fc != "") {
		document.getElementById("menu" + i).style.display = "block";
		document.getElementById("menu" + tek).style.display = "none";
	}
	tek = i;
}