​x
 
<html>
<body>
​
<script type="text/javascript">
image0="/i/eg_banner_w3school.gif"
href0="/index.html"
alt0="W3School.org.cn"
​
image1="/i/eg_banner_htmlref.gif"
href1="https://www.w3school.org.cn/tags/index.asp"
alt1="HTML 4.01 / XHTML 1.0 参考手册"
​
image2="/i/eg_banner_jsref.gif"
href2="https://www.w3school.org.cn/jsref/index.asp"
alt2="JavaScript 参考手册"
​
len=3
​
now=new Date()
now=now.getSeconds()
rnd=now%len
​
image=eval("image"+rnd)
href=eval("href"+rnd)
alt=eval("alt"+rnd)
​
document.write("<a href='" + href + "'>")
document.write("<img src='" + image + "' alt='" + alt + "'></a>")
</script>
​
<h3>请刷新该页面，您会看到广告条的变化。</h3>
​
</body>
</html>
​