function addClass(element,value){
  if (!element.className){
	  element.className = value;
	} else {
	  newClassName = element.className;
		newClassName += " ";
		newClassName += value;
		element.className = newClassName;
	}
}

function stripeList(){
  if (!document.getElementsByTagName) return false;
	var list = document.getElementById("songs");
  var listitems = list.getElementsByTagName("li");
	var odd = false;
	for (var i=0; i<listitems.length; i++){
	  if (odd == true){
  		  addClass(listitems[i].firstChild,"purple");
	  		odd = false;
		} else {
		    odd = true;
		}
	}
}

addLoadEvent(stripeList);