<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<link id="a2" rel="stylesheet" type="text/css" href="css1.css" />
<title>无标题文档</title>
<script type="text/javascript">
function anco()
{
var cho=document.getElementById('a2');
cho.href='css1.css';
}
function anco2()
{
var cho=document.getElementById('a2');
cho.href='css2.css';
}
</script>
</head>
<body>
<input type="button" value="红色" onclick="anco()" /><br>
<input type="button" value="蓝色" onclick="anco2()" /><br><br><br><br>
<a onclick="anco()" href="#">红色</a><br><br><br>
<a onclick="anco2()" href="#">蓝色</a>
</body>
</html>