                        課程
                    
                        /前端開(kāi)發(fā)
                        
                            /JavaScript
                        
                        /DOM事件探秘

哪里錯(cuò)了？禁止跳轉(zhuǎn)和阻止冒泡

<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>無(wú)標(biāo)題文檔</title>
<script type="text/javascript">
function btnMessage(){
?? ?alert("hello world1");
?? ?}
function btnMessage2(event){
?? ?alert(event.type);
?? ?}
function btnMessage3(event){
?? ?event.stopPropagation();
?? ?event.pretDefavenult();
?? ?}
window.onload = function(){
var btn2 = document.getElementById("btn2");
var btn3 = document.getElementById("btn3");
var box? = document.getElementById("box");
var btn4 = document.getElementById("btn4");
btn2.onclick = function(){
?? ?alert("hello world0");
?? ?}
box.onclick = function(){
?? ?alert("hello world00");
?? ?}

//btn2.onclick? = null;?? ?
//btn3.addEventListener('click',function(){alert(this.value);},false);
//btn3.removeEventListener('click',btnMessage,false);
//btn3.attachEvent('onclick',btnMessage);
??? var UntilHandler={
?? ?addHandler:function(element,type,handler){
?? ??? ?if(element.addEventListener){
?? ??? ??? ?element.addEventListener(type,handler,false);
?? ??? ?}else if(element.attachEvent){
?? ??? ??? ?element.attachEvent('on'+type,handler);
?? ??? ?}else{
?? ??? ??? ?element['on'+type] = handler;
?? ??? ?}
?? ?},
?? ?removeHandler:function(element,type,handler){
?? ??? ?if(element.removeEventListener){
?? ??? ??? ?element.removeEventListener(type,handler,false);
?? ??? ?}else if(element.detachEvent){
?? ??? ??? ?element.detachEvent('on'+type,handler);
?? ??? ?}else{
?? ??? ??? ?element['on'+type] = null;
?? ??? ?}
?? ?}
?? ?}
?? ?UntilHandler.addHandler(btn3,'click',btnMessage2);
?? ?UntilHandler.addHandler(bnt4,'click',btnMessage3);
??? //UntilHandler.removeHandler(btn3,'click',btnMessage2);

}
</script>
</head>
<body>
?? ?<div id = "box">
??????? <input type="button" name="btn" value="按鈕" onclick="btnMessage()">
??????? <input type="button" name="btn2" value="按鈕2" id="btn2">
??????? <input type="button" name="btn3" value ="按鈕3" id= "btn3">
??????? <a href= "http://idcbgp.cn/course/programdetail/pid/32" id = "btn4">跳轉(zhuǎn)</a>
??? </div>
<script>
</script>
</body>
</html>