用js动态增加的控件如何添加onclick方法？

function add(e){
    
        var container = document.getElementById('content');
        var text = document.getElementById(e).innerHTML;
        var newNode = document.createElement("span");
        newNode.innerHTML = text;
        container.appendChild(newNode);
       
        var ui =document.getElementById(e);
        ui.style.visibility="hidden";
        
        // 加上这段就可以了
            newNode.onclick = function(){
                container.removeChild(this);
                ui.style.visibility="visible";
            }
}

绑定事件的兼容写法：
function addEvent(obj,e,fun){
obj.attachEvent ? obj.attachEvent("on"+e,fun) : obj.addEventListener(e,fun,false);
}
//为xxx绑定click事件
addEvent(xxx, "click", function(){
//....

});