If you wanted to retrieve the object window.frames.url when you only have a array of string parts ['frames', 'url']

CrawlObject.js

/**
* Will give you the object from a set of arrays
*
* If you wanted to retrieve the object window.frames.url when you only have a array of string parts ['frames', 'url']
*/
function crawl(obj, keys) {
    var key = keys.shift();
    return keys.length == 0 ? obj[key] : crawl(obj[key], keys);
}