Custom field (instead of url) in the comments

Hello,

I would want to change the field of the default url, that commenters could write their country in it instead of their homepage. And I want to list the country besides the name of the commenter (“User” from “Country”). I found these codes, but it doesn’t work.
In comments.php:

<p><input type="text" name="country" id="country" size="22" />
<label for="country"><small>Country</small></label></p>


In functions.php:

<div class="comment-author vcard">
<?php echo get_avatar($comment,$size='48',$default='<path_to_url>' ); ?>
<span class="commenter-name"><?php comment_author_link(); ?></span> from <span class="commenter-name"><?php print $comment->extra_country; ?></span>
</div>


Any suggestions?

Thanks,
gas