<!DOCTYPE html>
<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>
<p>Click the button to change the value of the href attribute to "sun.htm" instead of "venus.htm" for the "venus" area in the image-map.</p>
<p><b>Note:</b> Try the link in the area before and after you have clicked the button!</p>
<button onclick="myFunction()">Try it</button>
<p id="demo"></p>
<script>
function myFunction() {
document.getElementById("venus").href = "sun.htm";
document.getElementById("demo").innerHTML = "The link now goes to sun.htm.";
}
</script>
</body>
</html>