Proboards: jump to best post (first unread or most recent) in a thread

gistfile1.html

<script type="text/javascript">
<!--
// Jump to the best post (first first unread or most recent) in a thread.
// Originally by Todge, but completely rewritten by Ben Loveridge.
if(document.location.href.match('board=')&&!document.location.href.match('action=')) {
    var table_cells = document.getElementsByTagName('td'),
        create_cell_click_fn = function(href) {
            return function() { if (!window.pb_bubble) { window.location.href = href; } };
        },
        cell, is_topic_cell, has_new_post, new_post_href, best_post_href, last_post_cell, last_post_groups, last_post_href;
    for(var i=0; i<table_cells.length; i++) {
        cell = table_cells[i];
        // the cell that lists the topic will always have the "windowbg" class and be either 43 or 48% width
        is_topic_cell = cell.className === "windowbg" && cell.width.match(/4(3|8)/);
        if(is_topic_cell) {
            // if there is a new post, the first child is an A tag which is a "NEW" icon
            has_new_post = cell.firstChild.nodeName === "A";
            new_post_href = has_new_post ? cell.firstChild.href : null;

            // the last cell always contains a link to the most recent post; grab the href
            last_post_cell = table_cells[i+4];
            last_post_groups = new RegExp("href=['\"']([^'\"']+)").exec(String(last_post_cell.onclick));
            last_post_href = last_post_groups && last_post_groups[1];

            // the "best" link is the a) first unread or b) most recent post.
            best_post_href = new_post_href || last_post_href;

            // ERROR, this should never happen, but don't throw exceptions in case it does
            // (this should only happen if Proboards changes their page layout)
            if (!best_post_href) { continue; }

            // make clicking on the cell always jump to the best candidate
            cell.onclick = create_cell_click_fn(best_post_href);

            // also replace the link href for the title link (which normally links to the first post)
            cell.getElementsByTagName('a')[has_new_post ? 1 : 0].href=best_post_href;
        }
    }
}
//-->
</script>