function addItem(listItems, id) {
	listItems[listItems.length] = id;
}

function buildNav(id, listItems) {
	var j=0;
	var parentElement = document.getElementById(id);
	var output = '';
	if (!parentElement) return;
	
	for(var i=0; i<listItems.length; i++) {
		j=i+1;
		if (j==listItems.length) {
			output += '<li>' + document.getElementById(listItems[i]).innerHTML + '</li>';
			parentElement.innerHTML=output;
			parentElement.style.visibility='visible';
			return;
		}
		idLength = listItems[i].split('.').length;
		nextIdLength = listItems[j].split('.').length;
		
		targetElement = document.getElementById(listItems[i]);
		if (idLength == nextIdLength) {
			// do nothing, output the html as is
			output += '<li>' + targetElement.innerHTML + '</li>';
		} else if (idLength < nextIdLength) {
			// next id is a sub, so we need to add an <ul> element
			output += '<li>' + targetElement.innerHTML + '<ul>';
		} else {
			// next id has moved back up a level, need to finish off the open ul and li elements
			output += '<li>' + targetElement.innerHTML + '</li></ul></li>';
		} 
	}
	parentElement.innerHTML=output;
	parentElement.style.visibility='visible';
}