方式一.<br>
<script>
function on(){
var img = document.getElementById("light");
img.src="image/bulb_on.png";
}
function off(){
var img = document.getElementById("light");
img.src="image/bulb_off.png";
}
</script>
<img id="light" onmouseover="on();" onmouseout="off();"
src="image/bulb_off.png" />
<hr/>
方式二.<br>
<script>
function onLight(img){
img.src="image/bulb_on.png";
}
function offLight(img){
img.src="image/bulb_off.png";
}
</script>
<img onmouseover="onLight(this);" onmouseout="offLight(this);"
src="image/bulb_off.png" />
</script>
注意图片的路径