Something Awful OP recoloring

Colors the posts of the thread OP yellow.

// ==UserScript==
// @name           Something Awful OP recoloring
// @description    Colors the posts of the thread OP yellow.
// @version        1.2
// @namespace      http://www.mathemaniac.org
// @include        *://forums.somethingawful.com/showthread.php?*
// @grant          GM_addStyle
// ==/UserScript==

// Rewritten with help from Shawn Moore (sartak.org)

GM_addStyle('.oppost { background-color: #FFF2AA !important; border-collapse: collapse } ');

var xpath = '//table[descendant::dt[contains(@class, "op")]]//td';
var it = document.evaluate(xpath, document, null, XPathResult.UNORDERED_NODE_ITERATOR_TYPE,null);
var node;
var nodes = new Array();
while (node = it.iterateNext()) {
    nodes.push(node);
}

while (node = nodes.pop()) {
    node.className += ' oppost';
}