[CarolinaKid]

Here is what i have done.
In functions.php

 if ($post[attachmentid]!=0 and $post[attachmentvisible]) {
                $post[attachmentextension]=strtolower(getextension($post[filename]));
                $post['attachlength'] = round(($post['attachlength'] / 1024), 1);
                $post['filename'] = censortext(htmlspecialchars($post['filename']));

In showthread.php

 post.*,post.username AS postusername,post.ipaddress AS ip,user.*,userfield.*,".iif($forum[allowicons],'icon.title as icontitle,icon.iconpath,','')."
        attachment.attachmentid,attachment.filename,LENGTH(attachment.filedata) AS attachlength,attachment.visible AS attachmentvisible,attachment.counter
        ".iif($avatarenabled,",avatar.avatarpath,NOT ISNULL(customavatar.avatardata) AS hascustomavatar,customavatar.dateline AS avatardateline","")."

Then in postbit attachment i have this

 <p><normalfont><img src="{imagesfolder}/attach/$post[attachmentextension].gif" width="16" height="16" border="0" alt="">Attachment: <a href="attachment.php?s=$session[sessionhash]&postid=$post[postid]" target="_blank">$post[filename]</a></normalfont><br>
<smallfont>This has been downloaded $post[counter] time, $post[attachlength]kb(s).</smallfont></p>