<!-- 把下面代码加到<body>区域中 -->
<style>
.style1 {background-color:#CCCCCC;border-left:1px solid #F5F5F5;border-top:1px solid #F5F5F5;border-right:1px solid #333333;border-bottom:1px solid #333333;width:80px;height:20px;}
.style2 {background-color:#CCCCCC;border-left:1px solid #000000;border-top:1px solid #000000;border-right:1px solid #F5F5F5;border-bottom:1px solid #F5F5F5;width:80px;height:20px;}
</style>
<table id=myButton class=style1><tr><td align=center>Button</td></tr></table>
<br><br>
<button onclick=myButton.className='style1'>弹起</button>
<button onclick=myButton.className='style2'>按下</button>