[LordJMann]

Works fine in Firefox 1.5.0.3

To make it double click, change:

<if condition="$forum[statusicon] == 'new' ">
<a href="#">
<img src="$stylevar[imgdir_statusicon]/forum_$forum[statusicon].gif" alt="$vbphrase[mark_this_forum_read_home]" title="$vbphrase[mark_this_forum_read_home]" onclick="ajaxMarkForumRead($forum[forumid])" id="mfarfh_$forum[forumid]" border="0" title=""/>
</a>
<else />
<img src="$stylevar[imgdir_statusicon]/forum_$forum[statusicon].gif" alt="" border="0" />
</if>

to

<if condition="$forum[statusicon] == 'new' ">
<a href="#">
<img src="$stylevar[imgdir_statusicon]/forum_$forum[statusicon].gif" alt="$vbphrase[mark_this_forum_read_home]" title="$vbphrase[mark_this_forum_read_home]" ondblclick="ajaxMarkForumRead($forum[forumid])" id="mfarfh_$forum[forumid]" border="0" title=""/>
</a>
<else />
<img src="$stylevar[imgdir_statusicon]/forum_$forum[statusicon].gif" alt="" border="0" />
</if>

Also, I'm not sure why the href tag is in there, you can safely remove it and things work fine.

To make it show a confirmation box after clicking, edit the plugins and change:

PHP Code:

$header .= '
    <script type="text/javascript">
        mfarfh_AJAX_Object = new vB_AJAX_Handler(true);
        
        function mfarfh_AJAX_Changeimage(idd)
        {

                   elm = document.getElementById("mfarfh_" + idd);
                   img = elm.src;
                   img = img.replace("_new", "_old");
                   elm.src = img;

        }
        
        function ajaxMarkForumRead(id)
        {
            mfarfh_AJAX_Object.send("forumdisplay.php?do=markread&f=" + id + "&mfarfh_id=" + id + "&mfarfh_ajax=true");
            mfarfh_AJAX_Changeimage(id)
        }
    </script>
'; 


To:

PHP Code:

$header .= '
    <script type="text/javascript">
        mfarfh_AJAX_Object = new vB_AJAX_Handler(true);
        
        function mfarfh_AJAX_Changeimage(idd)
        {

                   elm = document.getElementById("mfarfh_" + idd);
                   img = elm.src;
                   img = img.replace("_new", "_old");
                   elm.src = img;

        }
        
        function ajaxMarkForumRead(id)
        {
            if (confirm("Are you sure?"))
            {
                mfarfh_AJAX_Object.send("forumdisplay.php?do=markread&f=" + id + "&mfarfh_id=" + id + "&mfarfh_ajax=true");
                mfarfh_AJAX_Changeimage(id)
            }
        }
    </script>
'; 


Hope that helps.