两种事件的绑定方式

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>

<input type="button" value="按钮1" onclick="f()" /><br/>
<input type="button" value="按钮2" id="bt2" /><br/>
<script>
function f() {
alert("我被点击了")
}


var bt2 = document.getElementById("bt2");
bt2.onclick=function () {
alert("我bt2也被点击了...")
}

</script>
</body>
</html>