/**
 * Adds and removes classes to a list of links to allow keyboard accessibility
 *
 * @param string dropDownId
 * @param string hoverClass
 * @param int mouseOffDelay
 */
function dropdown(dropdownId, hoverClass, mouseOffDelay) {
	if(dropdown = document.getElementById(dropdownId)) {
		var listItems = dropdown.getElementsByTagName('li');
		for(var i = 0; i < listItems.length; i++) {
			listItems[i].onmouseover = function() { this.className = addClass(this); }
			listItems[i].onmouseout = function() {
				var that = this;
				setTimeout(function() { that.className = removeClass(that); }, mouseOffDelay);
				this.className = that.className;
			}
			
			var anchor = listItems[i].getElementsByTagName('a');
			anchor = anchor[0];
			anchor.onfocus = function() { tabOn(this.parentNode); }
			anchor.onblur = function() { tabOff(this.parentNode); }
		}
	}
	
	function tabOn(li) {
		if(li.nodeName == 'LI') {
			li.className = addClass(li);
			tabOn(li.parentNode.parentNode);
		}
	}
	
	function tabOff(li) {
		if(li.nodeName == 'LI') {
			li.className = removeClass(li);
			tabOff(li.parentNode.parentNode);
		}
	}
	
	function addClass(li) { return li.className + ' ' + hoverClass; }
	function removeClass(li) { return li.className.replace(hoverClass, ""); }
}