iframe ajax uploader

uploader.js

$('body').on('submit', 'form.remote', function (e) {
    e.preventDefault();
    var form = this;
    form.xhrSend(function (responseData) {
        form.reset();
        window.images.add(responseData.src)
    });
    return false
});

Object.defineProperty(HTMLFormElement.prototype, 'xhrSend', {value: 
(function () {
    var createIframe, setFormProperties;

    createIframe = function (name) {
        var iframe;
        iframe = window.document.createElement('iframe');
        iframe.setAttribute("id", name);
        iframe.setAttribute("name", name);
        iframe.setAttribute("width", "0");
        iframe.setAttribute("height", "0");
        iframe.setAttribute("border", "0");
        iframe.setAttribute("style", "width: 0; height: 0; border: none;");
        return iframe;
    };

    setFormProperties = function (form, name) {
        form.setAttribute("target", name);
        form.setAttribute("method", "post");
        form.setAttribute("enctype", "multipart/form-data");
        form.setAttribute("encoding", "multipart/form-data");
    };
    return function (callback) {
        var eventHandler, iframe, iframeId;
        var form = this;
        var iframe_name = 'upload_iframe_'+(new Date).valueOf();
        iframe = createIframe(iframe_name);
        form.parentNode.appendChild(iframe);
        window.frames[iframe_name].name = iframe_name;
        iframeId = window.document.getElementById(iframe_name);
        eventHandler = function () {
            var content;
            iframeId.removeEventListener("load", eventHandler, false);
            if (iframeId.contentDocument) {
                content = iframeId.contentDocument.body.innerHTML;
            } else if (iframeId.contentWindow) {
                content = iframeId.contentWindow.document.body.innerHTML;
            } else if (iframeId.document) {
                content = iframeId.document.body.innerHTML;
            }
            try {
                content = JSON.parse(content)
            } catch (e) {}
            callback(content);
            return setTimeout(function () {
                iframeId.parentNode.removeChild(iframeId)
            }, 250);
        };
        iframeId.addEventListener("load", eventHandler, true);
        setFormProperties(form, iframe_name);
        return form.submit();
    }
})()
});