Get Current Data In Cgridview

I have the following helper




array(

	'name' => 'stype',

	'value'=> 'isset($data->Product->type) ? $data->Product->type : " "',

	'filter'=> ZHtml::enumDropDownList( Product::model(),'type', 

			array('empty'=>'All','name'=>'ProductDetail[stype]'))

),






public static function enumDropDownList($model, $attribute, $htmlOptions=array())

{

   return CHtml::activeDropDownList( $model, $attribute,ZHtml::enumItem($model,  $attribute), $htmlOptions);

}



How do i specify/make the current selected item as the filter dropdown’s value