function toggleMenu(selectedElement) {

		var expander = selectedElement.parentNode.getElementsByTagName("img")[0];
		var list = selectedElement.parentNode.getElementsByTagName("ul")[0];

		if (expander.src.substring(expander.src.length - 8) == "plus.gif") {
			expander.src = expander.src.replace("plus.gif", "minus.gif");
			list.style.display = "block";
		}
		else {
			expander.src = expander.src.replace("minus.gif", "plus.gif");
			list.style.display = "none";
		}		
}

function hideSections(selectedSectionId) {

	var sections = document.getElementById("menu").getElementsByTagName("ul");

	for (i = 0; i < sections.length; i ++) {
		if (sections[i].id != "" && sections[i].id != selectedSectionId) {
			toggleMenu(sections[i]);
			hideParentSection(sections[i]);
		}
	}
}

function hideParentSection(section) {
	if (section.parentNode.nodeName.toLowerCase() == "li") {
		var parentSection = section.parentNode.parentNode;
		
		if (parentSection.id != "menu") {
			toggleMenu(parentSection);
		}
	}	
}

function hideAllSections() {
	hideSections("");
}

var menuLinks = document.getElementById("menu").getElementsByTagName("a");

for (i = 0; i < menuLinks.length; i ++) {
    if (menuLinks[i].className.indexOf("expander") > -1) {
        menuLinks[i].onclick = function() {
            toggleMenu(this);
            return false;
        }
    }
}