<html>
<body>
<img id="myImage" onclick="changeImage()" src="/demo/pic_bulboff.gif" width="100" height="180">
<p>点击灯泡，开启或关闭它。</p>
<script>
function changeImage() {
var image = document.getElementById("myImage");
if (image.src.match("bulbon")) {
image.src = "pic_bulboff.gif";
} else {
image.src = "pic_bulbon.gif";
}
}
</script>
</body>
</html>