Async script cross browser dom Ready detection

gistfile1.js

var _ready = function (doc) {
        function dispatch() {
            hasRun = 1;
            for (var i = 0, l = queue.length; i < l; i++) queue[i]()
        }
        var hasRun = 0,
        queue = [],
        d, e, f = !1,
        aElem = doc.createElement("a"),
        dloaded = "DOMContentLoaded",
        bind = "addEventListener",
        ready = "onreadystatechange";
        /^loade|c/.test(doc.readyState) && (hasRun = 1), doc[bind] && doc[bind](dloaded, me = function () {
            doc.removeEventListener(dloaded, me, f), dispatch()
        }, f), aElem.doScroll && doc.attachEvent(ready, d = function () {
            /^c/.test(doc.readyState) && (doc.detachEvent(ready, d) , dispatch());
        });
        var check = aElem.doScroll ? function (callback) {
            self != top ? hasRun ? callback() : c.push(callback) : ! function () {
                try {
                    aElem.doScroll("left")
                } catch (b) {
                    return setTimeout(function () {
                        check(callback)
                    }, 50)
                }
                callback()
            }()
        } : function (callback) {
            hasRun ? callback() : queue.push(callback)
        };
        return check;
    }(document);