Get Comment Reply Link Only?

I'm using comment_reply_link, for the reply links on every comment, but I want to use an image instead of text. I only need the link of the comment reply, not the whole thing. Codex wasn't helpful, neither the WP forums.

<span class="reply">
  <a href="<?php //comment reply link here ?>">
    <img src="<?php bloginfo('template_url') ?>/css/images/reply-button.png" alt="" />
  </a>
&开发者_如何学JAVAlt;/span>

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If you just need to replace the link text, add the image code as an argument:

<?php 
comment_reply_link( array ( 'reply_text' => '<img src="..." alt="Reply">' ) );
?>

Otherwise see the source code for the way the URL is generated.