Ich habe dieses Skript zum Hochladen von Dateien mit Ajax implementiert. Es funktioniert perfekt in anderen Browsern, außer im Explorer. Ich habe festgestellt, dass formData nicht von IE9 und weniger unterstützt wird. Gibt es Alternativen für formData in IE und ich möchte sauberes Javascript verwenden

    function doObjUploadExplorer(url, lnk_id, file, progress, success, content, frm, div_dlg, start_func){
    var file_input = null,
      frm_data = new FormData(),
      req;

    try {
        //firefox, chrome, safari etc
        req = new XMLHttpRequest();
    }

    catch (e) {
        // Internet Explorer Browsers
        req = new ActiveXObject("Microsoft.XMLHTTP");
    }


if (document.getElementById(file)) {
    file_input = document.getElementById(file);

    for (var i = 0; i < file_input.files.length; ++i) {
        frm_data.append(file, file_input.files[i]);
    }
}

req.upload.addEventListener('progress', function(e) {  //Event called while upload is in progress
    if (progress !== undefined
            && e.lengthComputable) {
        $('#' + progress).html('<font>Uploading... ' + Math.round((e.loaded / e.total) * 100) + '%</font>');
    }
});

req.upload.addEventListener('load', function(e) {  //Event called when upload is completed
    $('#' + progress).html('<font>Retrieving updated data...</font>');
});

req.upload.addEventListener('error', function(e) {  //Event called when an error is returned by the server
    alert('An error has occurred...');
});

req.addEventListener('readystatechange', function(e) {        
    if (this.readyState === 4) {
        if (this.status === 200) {
            if (content !== undefined) {
                $('#' + content).html(this.response);
            }

            if (success !== undefined) {
                showChkMark(success);
            }
        } else {
            console.log('Server replied with HTTP status: ' + this.status);
        }


        if (progress !== undefined) {
            $('#' + progress).hide();
        }

        if (div_dlg !== undefined) {
            $('#' + div_dlg).dialog('close');
        }

        $('#' + file)
        .attr('disabled', false)
        .val('');
    }
});

if (progress !== undefined) {
    $('#' + progress).show();
}

$('#' + file).attr('disabled', true);
url += (
        url.indexOf('?') === -1
        ? '?'
        : '&'
    );
url += 'lnk_id=' + lnk_id + '&file=' + file;
req.open('POST', url);
req.setRequestHeader('Cache-Control', 'no-cache');

if (start_func !== undefined) {
    start_func.apply();
    setTimeout(function() {
        req.send(frm_data);
    }, 500);
} else {
    req.send(frm_data);
}}