function hover(obj) {
	var el = obj.getElementsByTagName("ul")[0];
	
	if (el.style.display == "block") {
		el.style.display = "none";
		obj.className = obj.className.replace(new RegExp(" hover\\b"), "");
	}
	else {
		el.style.display = "block";
		obj.className += " hover";
	}
}

navHover = function() {
	var els = document.getElementById("sidenav").getElementsByTagName("li");
	for (var i=0; i<els.length; i++) {
		if (els[i].className == "nav_hover") {
			els[i].onmouseover = new Function("hover(this);");
			els[i].onmouseout = new Function("hover(this);");
		}
	}
};

window.onload = function() {
	navHover();
};