在magento侧边栏中显示热门标签

I am working on a magento site, and i want to add the popular tags blocks in right sidebar. I already added this code in tag.xml

<default>
    <!-- Mage_Tag -->
    <reference name="right">
        <block type="tag/popular" name="tags_popular" template="tag/popular.phtml"/>
    </reference>

</default>

But its not working. I tried this code in design/frontedn/default/theme/template/page/2columns-right.phtml

<?php echo $this->getLayout()->createBlock('tag/popular')->setTemplate('tag/popular.phtml')->toHtml(); ?>

But its too not working. am i missing something? is there a way to add the popular tags block in right sidebar in my theme??

I found the solution for my site. I had installed the demo catalog for Magento and added tags for those products. Now I've added the real categories and products and changed the store view to default catalog to new create a new Category. So Magento wasn't displaying the old catalog tags.

Now I've added new tags and it stared displaying in the sidebars.

So check for above case or there are following possibilities:

1. The tags are added but yet not approved.
2. The product's status is 'disabled'
3. The product's visibility is 'not individually visible'

For any of these cases the tag will not display.