var IframeOnClick = {
    resolution: 200,
    iframes: [],
    interval: null,
    Iframe: function () {
        this.element = arguments[0];
        this.cb = arguments[1];
    },
    track: function (element, cb) {
        this.iframes.push(new this.Iframe(element, cb));
        var _this = this;
        this.interval = setInterval(function () {
            _this.checkClick();
        }, this.resolution);
    },
    checkClick: function () {
        if (document.activeElement) {
            var activeElement = document.activeElement;
            for (var i in this.iframes) {
                if (activeElement === this.iframes[i].element) { // user is in this Iframe
                    this.iframes[i].cb.apply(window, []);
                    var btn = document.getElementById("btn")
                    btn.focus()
                }
            }
        }
    }
};
IframeOnClick.track(document.getElementById("iFrame"), function () {
    console.log(11111);
});