帮忙看看，加不上class

window.onload = function(){
var oEo = document.getElementById('eo');
var ulLi = oEo.getElementsByTagName('li');
for(var i=0; i<ulLi.length;i++){
//ulLi[i].index = i;
ulLi[i].onclick = function(){
for(var i=0;i<ulLi.length;i++){
removeClass(ulLi[i], 'cur');
}
addClass(this.className, 'cur');
}
}
function hasClass(obj, cls) {
return obj.className.match(new RegExp('(\\s|^)' + cls + '(\\s|$)'));
}
function addClass(obj, cls) {
if (!this.hasClass(obj, cls)) obj.className += " " + cls;
}
function removeClass(obj, cls) {
if (hasClass(obj, cls)) {
var reg = new RegExp('(\\s|^)' + cls + '(\\s|$)');
obj.className = obj.className.replace(reg, ' ');
}
}
}