<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title></title>
<style>
div {
width: 500px;
height: 500px;
background-color: black;
border: 5px solid red;
position: relative;
}
span {
position: absolute;
font-size: 40px;
color: yellow;
}
</style>
</head>
<body>
<input type="button" value="闪闪发光" id="bt"/>
<input type="button" value="停止" id="bt1"/>
<div id="dv">
</div>
<script src="common.js"></script>
<script>
my$("bt").onclick = function () {
timeId1 = setInterval(function () {
my$("dv").innerHTML = "<span>★</span>";
var x = parseInt(Math.random() * 500 + 1);
var y = parseInt(Math.random() * 500 + 1);
my$("dv").firstElementChild.style.left = x + "px";
my$("dv").firstElementChild.style.top = y + "px";
}, 10)
};
my$("bt1").onclick = function () {
clearInterval(timeId1);
};
</script>
</body>
</html>
