public function anular($retencion_id)
 {
     $message = '';
     $ret_data = $this->ci->generic_model->get('bill_retencion_venta', array('id' => $retencion_id), 'pagada', null, 1);
     $res = $this->ci->generic_model->update('bill_retencion_venta', array('estado' => '-1'), array('id' => $retencion_id));
     if ($res > 0) {
         $message .= success_info_msg('La retencion ha sido anulada correctamente');
     } else {
         return false;
     }
     return $message;
 }
echo warning_msg('Usuario y Clave para el acceso al sistema');
echo Open('div', array('class' => 'col-md-4 form-group'));
echo Open('div', array('class' => 'input-group'));
echo tagcontent('span', '<b>Usuario</b>: ', array('class' => 'input-group-addon'));
echo input(array('type' => 'text', 'name' => 'usu', 'id' => 'usu', 'placeholder' => 'Usuario', 'class' => 'form-control'));
echo Close('div');
echo Close('div');
echo Open('div', array('class' => 'col-md-4 form-group'));
echo Open('div', array('class' => 'input-group'));
echo tagcontent('span', '<b>Password</b>: ', array('class' => 'input-group-addon'));
echo input(array('type' => 'password', 'name' => 'pass', 'id' => 'pass', 'placeholder' => '********', 'class' => 'form-control'));
echo Close('div');
echo Close('div');
echo Close('div');
echo Open('div', array('class' => 'col-md-12'));
echo success_info_msg('Datos Complementarios');
echo Open('div', array('class' => 'col-md-4 form-group'));
echo Open('div', array('class' => 'input-group'));
echo tagcontent('span', '<b>Dni/Pasaporte</b>: ', array('class' => 'input-group-addon'));
echo input(array('type' => 'text', 'name' => 'ced_estu', 'id' => 'ced_estu', 'placeholder' => 'Digete el NªIdent.', 'class' => 'form-control'));
echo Close('div');
echo Close('div');
echo Open('div', array('class' => 'col-md-4 form-group'));
echo Open('div', array('class' => 'input-group'));
echo tagcontent('span', '<b>Nombre</b>: ', array('class' => 'input-group-addon'));
echo input(array('type' => 'text', 'name' => 'name_estu', 'id' => 'name_estu', 'placeholder' => 'Digete el Nombre', 'class' => 'form-control'));
echo Close('div');
echo Close('div');
echo Open('div', array('class' => 'col-md-4 form-group'));
echo Open('div', array('class' => 'input-group'));
echo tagcontent('span', '<b>Apellido</b>: ', array('class' => 'input-group-addon'));