class="row">
    <div class="span12">
      <input type="text" class="span2" placeholder="span2">
    </div><!--/span-->
  </div><!--/row-->
  <div class="row">
    <div class="span12">
      <input type="text" class="span3" placeholder="span3">
    </div><!--/span-->
  </div><!--/row-->
  <div class="row">
    <div class="span12">
      <input type="text" class="span4" placeholder="span4">
    </div><!--/span-->
  </div><!--/row-->
  <div class="row">
    <div class="span12">
      <input type="text" class