gridview - Add filter for some columns only in yii tbgridview -

i'm new in yii , have problem tbgridview.

can make gridview have filter columns only? example, have these grid view:

$this->widget( 'bootstrap.widgets.tbgridview', array(         'id'             => 'report-purchase-grid',         'template'       => "<div>{pager}</div><div style='float:left;'>{summary}</div><div class='clear'>&nbsp;</div>\n{items}\n<div>{pager}</div><div style='float:left;'>{summary}</div><div class='clear'>&nbsp;</div><br/>",         'dataprovider'   => $model->getreport(),         'selectablerows' => 2,         'columns'        => array(             array(                 'name'   => 'months',                 'filter' => chtml::activetextfield($model, 'months'),                 'header' => 'month',             ),             array(                 'name'   => 'transaction_date',                 'header' => 'transaction date'             ),             array(                 'name'   => 'code',                 'header' => 'purchase code',             ),          ), )), 

if use filter below dataprovider, end have filter in column. want have filter in months. tried using filter below months above example, no luck too.

does know how that? appreciate if can tell me.

'columns'=>array(       array(         'name'=>'columnname',         'visible'=>false           ),        )