jQuery
<!DOCTYPE html>
<html lang="ja-JP">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width,user-scalable=yes,initial-scale=1.0,minimum-scale=1.0,maximum-scale=1.5">
<title></title>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script>
<script>
$(function(){
$("label,:checkbox").click(function(){
$("label").css("background","");
$(":checked").each(function(){
$("label[for='" + $(this).attr("id") + "']").css("background","#CCCCCC");
});
});
});
</script>
<body>
スキル：
<input type="checkbox" name="xhtml" value="XHTML" id="xhtml">
<label for="xhtml">XHTML</label>
<input type="checkbox" name="css" value="CSS" id="css">
<label for="css">CSS</label>
<input type="checkbox" name="javascript" value="JavaScript" id="javascript">
<label for="javascript">JavaScript</label>
<input type="checkbox" name="php" value="PHP" id="php">
<label for="php">PHP</label>
</body>
</html>