代码示例：（标识：html_script_attribute）
<!DOCTYPE html>
<html>
<body>
<h1>我的第一段 JavaScript</h1>
<p>在这里，JavaScript 更改了图像的 src 属性。</p>
<script>
function light(sw) {
var pic;
if (sw == 0) {
pic = "/static/demo/images/eg_bulboff.gif"
} else {
pic = "/static/demo/images/eg_bulbon.gif"
}
document.getElementById('myImage').src = pic;
}
</script>
<img id="myImage" src="/static/demo/images/eg_bulboff.gif" width="109" height="180">
<p>
<button type="button" onclick="light(1)">开灯</button>
<button type="button" onclick="light(0)">关灯</button>
</p>
</body>
</html>
