javascript - jQuery Ajax File Upload

Can I use the following jQuery code to perform file upload using POST method of an ajax request ?

$.ajax({
    type: "POST",
    timeout: 50000,
    url: url,
    data: dataString,
    success: function (data) {
        alert('success');

        return false;
    }
});

If it is possible, do I need to fill data part? Is it the correct way? I only POST the file to the server side.

I have been googling around, but what I found was a plugin while in my plan I do not want to use it. At least for the moment.

Answer

file upload is not possible through ajax.

You can upload file, without refreshing page by using IFrame.
you can check further detail here

UPDATE:

With XHR2, File upload through AJAX is supported. E.g. through FormData object, but unfortunately it is not supported by all/old browsers.

FormData support starts from following desktop browsers versions.
IE 10+,
Firefox 4.0+,

Chrome 7+,
Safari 5+,
Opera 12+

For more detail, see MDN link