<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title></title>
<style>
div {
width: 300px;
height: 200px;
background-color: pink;
}
</style>
</head>
<body>
<div id="dv"></div>
<input type="button" id="bt" value="变透明"/>
<script src="common.js"></script>
<script>
my$("bt").onclick = function () {
var opacity = 10;
var timeId = setInterval(function () {
opacity--;
if (opacity <= 0) {
//清理定时器
clearInterval(timeId);
}
my$("dv").style.opacity = opacity / 10;
}, 200)
};
</script>
</body>
</html>
