开始界面如图：
复制代码 代码如下:
<head>
<title></title>
<script type="text/javascript">
function UpdateImg() {
//document.getElementById('img1').setAttribute('src', 'images/2.jpg');
var dogandcat = document.getElementsByName('dogandcat'); //获取所有name=dogandcat的单选按钮
for (var i = 0; i < dogandcat.length; i++) {
if (dogandcat[i].checked == true) {
var value = dogandcat[i].getAttribute('value');
switch (value) {
case '2':
document.getElementById('img1').setAttribute('src', 'images/2.jpg');
break;
case '3':
document.getElementById('img1').setAttribute('src', 'images/3.jpg');
break;
case '4':
document.getElementById('img1').setAttribute('src', 'images/4.jpg');
break;
case '6':
document.getElementById('img1').setAttribute('src', 'images/6.jpg');
break;
}
}
}
}
</script>
</head>
<body>
<img id="img1" src="images/9.jpg" width="200px" height="200px" />
<br />
<input type="button" value="改变图片" />
<br />
<input id="Radio1" name="dogandcat" type="radio" value="2" />忧伤的小狗
<input id="Radio2" name="dogandcat" type="radio" value="3"/>卖萌的小狗
<input id="Radio3" name="dogandcat" type="radio" value="4"/>愤怒的小狗
<input id="Radio4" name="dogandcat" type="radio" value="6"/>可爱的小猫
</body>
下面是程序运行时的界面：点击不同的按钮图片是不一样的
