function getElem(id) {
	return document.getElementById(id);
}


//-----------------------------------------
// Represents a Navigation Menu object 
// Parameters:
//		id - the id of the list
//		selectedIndex - the selected item on the menu (always on)
//		bullet - the HTML code to show as a bullet
//		bulletPosition - the position of the bullet (left or right)
//-----------------------------------------
function NavigationMenu(id, selectedIndex, bullet, outClass, overClass, onClass) {
	this.root = document.getElementById(id);
	this.bullet = bullet;
	this.outClass = outClass;
	this.overClass = overClass;
	this.onClass = onClass;

	var menuItems = this.root.getElementsByTagName("li");
	for (var i=0; i<menuItems.length; i++) {
		link = menuItems[i].getElementsByTagName("a")[0];
	
		if (i == selectedIndex){
			this.setAlwaysSelected(link);
		} else {
			this.setMouseoutEvent(link);
			this.setMouseoverEvent(link);
		}
	}
}

NavigationMenu.prototype = {
    
    setAlwaysSelected: function(elem) {
		elem.parentNode.getElementsByTagName("div")[0].innerHTML = this.bullet;
		elem.parentNode.className = this.onClass;
    },

    setMouseoverEvent: function(elem) {
		var bullet = this.bullet;
		var overClass = this.overClass;
		elem.onmouseover = function() {
			elem.parentNode.getElementsByTagName("div")[0].innerHTML = bullet;
			elem.parentNode.className = overClass;
		};
    },

    setMouseoutEvent: function(elem) {
		var outClass = this.outClass;
		elem.onmouseout = function() {
			elem.parentNode.getElementsByTagName("div")[0].innerHTML = '&nbsp;';
			elem.parentNode.className = outClass;
		};
    }

}