public function previewImage($width = 190, $height = 190)
{
$preview = Yii::app()->getTheme()->getAssetsUrl() . '/images/thumbnail.png';
if (isset($this->preview)) {
$preview = $this->preview->getImageUrl($width, $height);
} elseif (!isset($this->preview) && $this->imagesCount > 0) {
$preview = $this->images[0]->getImageUrl($width, $height);
}
return $preview;
}