<html>
<head>
<script type="text/javascript">
function changeBorder()
{
document.getElementById('myTable').border="10"
}
</script>
</head>
<body>
<table border="1" id="myTable">
<tr>
<td>100</td>
<td>200</td>
</tr>
<td>300</td>
<td>400</td>
</table>
<br />
<input type="button" onclick="changeBorder()" value="改变边框">
</body>
</html>