The following code shows how to mark response span3 layout.
<!DOCTYPE html>
<html>
<head>
<script type='text/javascript'
src='http://code.jquery.com/jquery-1.9.1.js'></script>
<link rel="stylesheet" type="text/css"
href="http://netdna.bootstrapcdn.com/twitter-bootstrap/2.3.2/css/bootstrap-combined.min.css">
<style type='text/css'>
.resp {<!--from www . java 2 s . c om-->
background-color: red;
height: 50px;
color: white;
}
.unresp {
background-color: green;
height: 50px;
color: white;
}
.new3 {
float: left;
min-height: 1px;
margin-left: 20px;
width: 220px;
}
</style>
</head>
<body>
<div class="container">
<div class="row">
<div class="span3 resp">Responsive column</div>
<div class="span3 resp">Responsive column</div>
<div class="span3 resp">Responsive column</div>
<div class="span3 resp">Responsive column</div>
</div>
<div class="row">
<div class="new3 unresp">Responsive column</div>
<div class="new3 unresp">Responsive column</div>
<div class="new3 unresp">Responsive column</div>
<div class="new3 unresp">Responsive column</div>
</div>
</div>
</body>
</html>