PageController (saveAction function)

    public function saveAction()
    {
        $id     = $this->getRequest()->getParam('id');
        $model  = Mage::getModel('amshopby/page');

        $data   = $this->getRequest()->getPost();
        if (!$data) {

        }

        //upload images
        $path = Mage::getBaseDir('media') . DS . 'amshopby' . DS;
        $imagesTypes = array('big', 'small', 'medium', 'small_hover', 'page');
        foreach ($imagesTypes as $type){
            $field = 'img_' . $type;

            $isRemove = isset($data['remove_' . $field]);
            $hasNew   = !empty($_FILES[$field]['name']);

            try {
                // remove the old file
                if ($isRemove || $hasNew){
                    $oldName = $model->getData($field);
                    if ($oldName){
                         @unlink($path . $oldName);
                         $data[$field] = '';
                    }
                }

                // upload a new if any
                if (!$isRemove && $hasNew){
                    $newName = $type . $id;
                    $newName .= '.' . strtolower(substr(strrchr($_FILES[$field]['name'], '.'), 1));

                    $uploader = new Varien_File_Uploader($field);
                    $uploader->setFilesDispersion(false);
                    $uploader->setAllowRenameFiles(false);
                    $uploader->setAllowedExtensions(array('png','gif', 'jpg', 'jpeg'));
                    $uploader->save($path, $newName);
                    $data[$field] = $newName;
                }
            }

            catch (Exception $e) {
                Mage::getSingleton('adminhtml/session')->addError($e->getMessage());
            }
        }

        try {
            $model->setData($data)->setId($id);

            $this->prepareForSave($model);

            $cond = array();
            for ($i=0; $i < $model->getNum(); ++$i){
                $cond[] = array(
                    'attribute_code' => $model->getData('attr_' . $i),
                    'attribute_value' => $model->getData('option_' . $i)
                );
            }

            $model->setCond(serialize($cond));

            $model->save();
            Mage::getSingleton('adminhtml/session')->setFormData(false);

            $msg = Mage::helper('amshopby')->__('Page has been successfully saved');
            Mage::getSingleton('adminhtml/session')->addSuccess($msg);
            if ($this->getRequest()->getParam('continue')){
                $this->_redirect('*/*/edit', array('id' => $model->getId()));
            }
            else {
                $this->_redirect('*/*');
            }
        }
        catch (Exception $e) {
            Mage::getSingleton('adminhtml/session')->addError($e->getMessage());
            Mage::getSingleton('adminhtml/session')->setFormData($data);
            $this->_redirect('*/*/edit', array('id' => $id));
        }
    }