function openNav(obj) {
	closeNav(obj);
	var button = obj;
	var obj = obj+"|sub";


	var stat = document.getElementById(obj).style.display;


	if (stat == "block") {
		document.getElementById(obj).style.display = "none";
		document.getElementById(button).style.backgroundColor = "";
	document.getElementById(button).style.color = "";
	} else {
		document.getElementById(obj).style.display = "block";
		document.getElementById(button).style.backgroundColor = "#DA500F";
		document.getElementById(button).style.color = "#ffffff";
	}
}

function closeNav(obj) {
	tree = ['HOTEL', 'ZIMMER', 'TAGEN', 'ESSEN', 'RESERVIEREN', 'KONTAKT'];

	for (var i=0; i<tree.length; i++) {

		if (obj!=tree[i]) {
			document.getElementById(tree[i]+"|sub").style.display = "none";
		} else {

		}
		document.getElementById(tree[i]).style.backgroundColor = "";
		document.getElementById(tree[i]).style.color ="";


	}

				document.getElementById(obj).style.backgroundColor = "#DA500F";
			document.getElementById(obj).style.color = "#ffffff";
}