confirm--显示一个带有指定消息和 OK 及取消按钮的对话框
用户点击ok返回true，点击取消返回false
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<script type="text/javascript">
function confirmDemo(){
var boo = window.confirm("你带刺吗？");
if(boo){
alert("111");
}else{
alert("222");
}
}
</script>
<button onclick="confirmDemo();">confirm</button>
</body>
</html>