Untitled

<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <link rel="stylesheet" media="all" href="regular_styles.css">
    <link rel="stylesheet" media="(max-width: 600px)" href="small_screen.css" id="small">
</head>
<body>

    <div class="a">Hello</div>
    <input id="b" type="button" value="Change" />

    <script src="jquery.min.js"></script>
    <script>
        $('#b').click(function(){
            // change the media query perimeter to "all"
            $('#small').attr('media', 'all');
        });
    </script>
</body>
</html>