<html>
<body>
<img id="planets"
src="/img/eg_planets.jpg"
usemap="#planetmap" />
<map name="planetmap">
<area
shape="circle"
coords="180,139,14"
href ="/example/html/venus.html"
target ="_blank"
alt="Venus" />
</map>
<p>usemap 属性的值等于 =
<script type="text/javascript">
x=document.getElementById('planets');
document.write(x.useMap);
</script>
</p>
</body>
</html>