小球上下跳动
简介 点击鼠标后，小球在页面上弹跳，最后停留在页面底部，很好玩的
步骤一: 请将下面的原代码插入到<body>下面
<script language="JavaScript" for="body" event="onclick">
handleClick();
</script>

<SCRIPT LANGUAGE="JavaScript">
<!-- Begin
var iter = 0;
var setId = 0;
var down = true;
var up = false;
function handleClick() {
if (setId != 0)
window.clearInterval(setId);
if (ball.style.display == "")
ball.style.display = "none";
ball.style.left = event.offsetX - 20;
ball.style.top = event.offsetY - 20;
iter = 0;
ball.style.display = "";
setId = window.setInterval("return generateGravity();", 20);
}
function generateGravity() {
if ((parseInt(ball.style.top)+iter < ball.offsetParent.offsetHeight - 55) && down) {
ball.style.top = parseInt(ball.style.top,10) + iter;
iter++;
return;
}
else {
if ((parseInt(ball.style.top)< ball.offsetParent.offsetHeight - 55) && down) {
ball.style.top = ball.offsetParent.offsetHeight - 50;
return;
}
down = false;
up = true;
if (iter < 0 && parseInt(ball.style.top) > ball.offsetParent.offsetHeight - 55) {
window.clearInterval(setId);
setId = 0;
}
if (parseInt(ball.style.top) > 0 && up && iter >= 0) {
ball.style.top = parseInt(ball.style.top,10) - iter;
iter--;
if (iter%3 == 0)
iter--;
return;
}
down = true;
up = false;
  }
}
// End -->
</script>
<div id="ball" style="display:none; position:absolute; left:10; top:10; height:40; width:40"><img src="ball.gif" height=29 width=30></div>
步骤二: , 把<body>中的内容改为：
<body bgColor=#fef4d9 id="body">
步骤三: , 请下载如下图片到与文件同一目录下