window.onmouseover = initialise; // doesn't work in IE, but makes the dropnav work immediately in Firefox
window.onload = initialise; // works in IE, but won't take effect until page has fully loaded

function initialise() {
	var menu_link = get_menu_link();
	var list = get_dropnav_ul();

	menu_link.onmouseover = openNav;
	menu_link.onmouseout = closeNav;
	menu_link.onclick = function () { return false;};

	list.onmouseover = openNav;
	list.onmouseout = closeNav;
}

function get_dropnav_ul() {
	return document.getElementById('droplist');
}

function get_menu_link() {
	return document.getElementById('menulink');
}

function openNav() {
	change(this, 'block');
}

function closeNav() {
	change(this, 'none');
}

function change(el, displayMode) {
	if (el.tagName == 'UL') {
		el.style.display = displayMode;
		return;
	}

	if (el.tagName == 'A') {
		var list = get_dropnav_ul();
		list.style.display = displayMode;
	}
}