Как альтернатива:
<!doctype html>
<html>
<head>
<meta charset="utf-8" />
<title> test </title>
<link rel="stylesheet" type="text/css" href="base.css"/>
<link rel="stylesheet" type="text/css" href="style0.css" title="0"/>
<link rel="stylesheet" type="text/css" href="style1.css" title="1"/>
</head>
<body>
<script>
function setStyle(s) {
for(i=0; (a=document.getElementsByTagName("link")[i]); i++) {
if(a.getAttribute("title")) {
a.disabled=true;
if(a.getAttribute("title")==s) a.disabled=false;
}
}
}
//setStyle(0);
//setStyle(1);
</script>
<input type="button" name="" value="0" onclick="setStyle(0)"/>
<input type="button" name="" value="1" onclick="setStyle(1)"/>
</body>
</html>