JavaScript实现表格边框颜色自动切换

<html>
<head>
<meta charset="utf-8">
<title>表格边框变换颜色代码</title>
</head>
<body>
<table border="0" width="261" id="change_jb51_net" style="border:1px solid red">
<tr>
<td>等待，然后注意看边框是不是变色了?</td>
</tr>
</table>
<script>
<!--
function hovertreecolor(){

if (change_jb51_net.style.borderColor=="blue")
change_jb51_net.style.borderColor="red"
else
change_jb51_net.style.borderColor="blue"
}
setInterval("hovertreecolor()", 3000)
</script>
</body>
</html>