target 属性可设置或返回在何处打开区域中的 link-URL。
areaObject.target=_blank|_parent|_self|_top
四个保留的目标名称：
The following example changes the target of the link in the image-map:
<html>
<head>
<script type="text/javascript">
function changeTarget()
{
document.getElementById('venus').target="_blank"
}
</script>
</head>
<body>
<img src ="planets.gif"
width="145" height="126"
alt="Planets"
usemap ="#planetmap" />
<map name ="planetmap">
<area shape ="circle" coords ="124,58,8"
href ="venus.htm" id="venus" />
</map>
<br />
<input type="button" onclick="changeTarget()"
value="Change target" />
</body>
</html>