public function export($id = null, $pag = 1)
    {
        $tickets = $this->db->select('t.*, g.group_name, p.first_name, p.last_name')
        ->from('poll_tickets AS t')
        ->join('poll_groups AS g', 'g.id = t.ticket_group_id', 'left')
        ->join('profiles AS p', 'p.user_id = t.created_by', 'left')
        ->where('t.ticket_group_id', $id)
        ->get()
        ->result();
        $data = array();

        $i = 0;



@mysql_connect("localhost","intranet","Poblado2017");
mysql_select_db("intranet_elpoblado");

$cons="SELECT group_name,created FROM `default_poll_groups` where id='$id'";
$resu=mysql_query($cons);

while($row=mysql_fetch_row($resu)){

	$nomb_encu=$row[0];
	$fech_regi=$row[1];

}


$cons="SELECT id,name FROM `default_poll_custom_fields` where group_id='$id' order by 1";
$resu=mysql_query($cons);

$cont_fila_data=0;
$cont_colu_data=4;

$data[0][0]="Datos de la encuesta";
$data[0][1]="Usuario";
$data[0][2]="Fecha";

$preguntas=array();
$total_preguntas=0;

while($row=mysql_fetch_row($resu)){

	$id_field=$row[0];
	$name=utf8_encode($row[1]);

  $preguntas[$total_preguntas]=$id_field;
  $total_preguntas+=1;

	$data[$cont_fila_data][$cont_colu_data]=$name;

	$cont_colu_data+=1;

}

//	Consultar usuarios que han realizado la encuesta

$fila=1;

$cons="SELECT distinct a.user_id,first_name,last_name FROM `default_poll_custom_user` a,default_profiles b where a.user_id=b.user_id and field_id in (select id from default_poll_custom_fields where group_id='$id') and first_name is not null and first_name!='' order by 2";
$resu=mysql_query($cons);

while($row=mysql_fetch_row($resu)){

	$user_id=$row[0];
	$first_name=utf8_encode($row[1]);
	$last_name=utf8_encode($row[2]);

	$colu=3;

	//	Respuestas de los usuarios

  $data[$fila][0]=$nomb_encu;
	$data[$fila][1]=$first_name." ".$last_name;
	$data[$fila][2]=$fech_regi;

  for($c=0;$c<$total_preguntas;$c++){

    $pregunta=$preguntas[$c];

    $cons2="SELECT value FROM `default_poll_custom_user` where user_id='$user_id' and field_id='$pregunta' order by ticket_id desc limit 1";
    $resu2=mysql_query($cons2);
    $tota2=mysql_num_rows($resu2);

    if($tota2>0){

      while($row2=mysql_fetch_row($resu2)){

        $valor=$row2[0];

        if(count(explode('value',$valor))>1)
          $valor="";

        $data[$fila][$colu]=$valor;

        $colu+=1;

      }

    }else{

      $valor="";

      $data[$fila][$colu]=$valor;

      $colu+=1;

    }

  }

	$fila+=1;

}

$this->load->library(array('PHPExcel_1.8.0/PHPExcel'));

$doc = new PHPExcel();
$doc->setActiveSheetIndex(0);

$doc->getActiveSheet()->fromArray($data, null, 'A1');
header('Content-Type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet');
header('Content-Disposition: attachment;filename="export.xls"');
header('Cache-Control: max-age=0');

$writer = PHPExcel_IOFactory::createWriter($doc, 'Excel5');

$writer->save('php://output');
}