links 集合可返回对文档中所有 Area 和 Link 对象的引用。
document.links[]
<html>
<body>
<img src="planets.gif"
width="145" height="126"
usemap="#planetmap" />
<map name="planetmap">
<area id="venus" shape="circle"
coords="124,58,8"
alt="Venus"
href="venus.htm" />
</map>
<br />
Number of links in this document:
<script type="text/javascript">
document.write(document.links.length)
</script>
</body>
</html>