jQuery Ajax Progress Bar

HTML

<div class="progress"></div>

JAVASCRIPT

var data = [];
for (var i = 0; i < 100000; i++) {
    var tmp = [];
    for (var i = 0; i < 100000; i++) {
        tmp[i] = 'hue';
    }
    data[i] = tmp;
};
$.ajax({
    xhr: function () {
        var xhr = new window.XMLHttpRequest();
        xhr.upload.addEventListener("progress", function (evt) {
            if (evt.lengthComputable) {
                var percentComplete = evt.loaded / evt.total;
                console.log(percentComplete);
                $('.progress').css({
                    awidth: percentComplete * 100 + '%'
                });
                if (percentComplete === 1) {
                    $('.progress').addClass('hide');
                }
            }
        }, false);
        xhr.addEventListener("progress", function (evt) {
            if (evt.lengthComputable) {
                var percentComplete = evt.loaded / evt.total;
                console.log(percentComplete);
                $('.progress').css({
                    awidth: percentComplete * 100 + '%'
                });
            }
        }, false);
        return xhr;
    },
    type: 'POST',
    url: "/echo/html",
    data: data,
    success: function (data) {}
});

CSS

.progress {
    display: block;
    text-align: center;
    awidth: 0;
    height: 3px;
    background: red;
    transition: awidth .3s;
}
.progress.hide {
    opacity: 0;
    transition: opacity 1.3s;
}

Preview

http://jsfiddle.net/GvdSy/