.pmk-FlowPanel {
}

.cw-FlowPanel-checkBox {
  margin-right: 20px;
}

<?php 
include_once 'phpmoko/ui/Form/CheckBox.php';
include_once 'phpmoko/ui/FlowPanel.php';

class ModuleDemo implements WebModule
{
  function getWidget()
  {
    // Create a Flow Panel
    $flowPanel = new FlowPanel();
    $flowPanel->setId("cwFlowPanel");

    // Add some content to the panel
    for ($i = 0; $i < 30; $i++) {
      $checkbox = new CheckBox('Item '.$i);
      $checkbox->addStyleName('cw-FlowPanel-checkBox');
      $flowPanel->add($checkbox);
    }

    // Return the content
    return $flowPanel;
  }
}
?>