JavaScript动态修改HTML表格边框宽度

<!DOCTYPE html>
<html>
<head>
<script>
function changeBorder()
{
document.getElementById('myTable').border="10";
}
</script>
</head>
<body>
<table border="1" id="myTable">
<tr>
<td>100</td>
<td>200</td>
</tr>
<tr>
<td>300</td>
<td>400</td>
</tr>
</table>
<br>
<input type="button" onclick="changeBorder()"
value="Change Border">
</body>
</html>