The following code shows how to use fluid row and span12.
<!DOCTYPE html>
<html>
<head>
<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'>
html, body {<!-- w w w .j a v a 2 s .c o m-->
height: 100%
}
#side-panel {
float: left;
width: 240px;
padding: 10px 20px 10px 20px;
height: 100%;
background-color: #1db34f;
border-right: 1px solid #dddddd;
text-align: center;
}
#center-panel {
margin-left: 280px;
background-color: #ddd;
text-align: center;
}
#center-panel .row-fluid {
overflow: auto;
}
#center-panel .large {
height: 400px;
padding: 10px;
background-color: #f17f49
}
</style>
</head>
<body>
<div id="side-panel">
<p>I'm the side panel</p>
</div>
<div id="center-panel" class="container-fluid">
<p>I'm the center panel</p>
<div class="row-fluid">
<div class="span12">
<p class="large">First row</p>
</div>
</div>
<div class="row-fluid">
<div class="span12">
<p class="large">Second row</p>
</div>
</div>
</div>
</body>
</html>