<!DOCTYPE html>
<html>
<body>
<script>
function changeImage()
{
element=document.getElementById('myimage')
if (element.src.match("bulbon"))
element.src="/img/eg_bulboff.gif";
}
else
element.src="/img/eg_bulbon.gif";
</script>
<img id="myimage" onclick="changeImage()" src="/img/eg_bulboff.gif">
<p>点击灯泡来点亮或熄灭这盏灯</p>
</body>
</html>