Magento - 在产品页面上嵌入图片

I've embedded some extra pictures and videos on my product pages, but when I create a new without setting a picture, Magento creates an error because it cannot find the picture, that is not set. I've created an attribute in Magento named embed3, an image attribute. Then I made this snippet, which works great - except if no pictures are chosen Magento fails:

<?php 
           $video3 = $_product->getEmbed3();
            if (isset($video3)){
                echo '<img src="';
                echo $this->helper('catalog/image')->init($_product, 'embed3');
                echo '"/>';
            }
            else 
            {
            }
            ?>

It's crude and ugly - I know, any suggestions/help will be much appreciated

Sadly that didn't work @F. Haymar d'Ettory :( it only created errors on all my products. But I found out that, while it works well on products I've created in the past, and products with pictures isset was also working, when creating new products and not setting a picture, Magento set it as "no_selection" - and the isset then think's that theres actually an image set, but here is not. So by creating this:

if (isset($video3)&&($video3 != 'no_selection')){

it works again, still not pretty but it works.

Are you using this snippet in product view?

Use the following instead of $video3 = $_product->getEmbed3(). getAttribute() always exists for a product resource, while magic methods don't.

$video3 = $_product->getResource()->getAttribute('embed3');