flot not shown

$data = array(array('11:19',3809.0), array('11:20',3808.0), array('11:21',3808.0), array('11:22',3809.0), array('11:23',3807.0));
  $d1 = new flotData($data);
  $d1->label = t('Example data 1');
  $d1->series =1;
  //$d2 = new flotData(array(array(0, 8), array(3, 5), array(8, 0.5)));
//  $d2->label = t('Example data 2');
  
  $variables = array(
    'data' => array($d1),
    'element' => array(
      'id' => 'flot-example-normal',
      'class' => 'flot-example',
      'style' => "width:1200px;height:600px",
    ),
    'legend' => TRUE,
    'zoom' => FALSE,
    'options'=>$options
  );
  return theme('flot_graph', $variables);

I update the flot_example module code, and want to the X to show date(H:i), but none result, as picture.