HTML5, CSS3 and JavaScript demo

<!DOCTYPE html>
<html>
<head>
<title>HTML5, CSS3 and JavaScript demo</title>
</head>
<body>

<div class="mainTable">
            <div class="topRow">
                <div class="cell1 span3">
                  <div class="span3"                style="height:50px; background-color:white; float:left;">1</div>
                </div>

</div>

</body>
</html>