Super Simple Ajax File Upload (XHR2)

// Ajax File upload with jQuery and XHR2
// Sean Clark http://square-bracket.com
// xhr2 file upload
	// data is optional
	$.fn.upload = function(remote,data,successFn,progressFn) {
		// if we dont have post data, move it along
		if(typeof data != "object") {
			progressFn = successFn;
			successFn = data;
		}
		return this.each(function() {
			if($(this)[0].files[0]) {
				var formData = new FormData();
				formData.append($(this).attr("name"), $(this)[0].files[0]);

				// if we have post data too
				if(typeof data == "object") {
					for(var i in data) {
						formData.append(i,data[i]);
					}
				}

				// do the ajax request
				$.ajax({
					url: remote,
					type: 'POST',
					xhr: function() {
						myXhr = $.ajaxSettings.xhr();
						if(myXhr.upload && progressFn){
							myXhr.upload.addEventListener('progress',function(prog) {
								var value = ~~((prog.loaded / prog.total) * 100);

								// if we passed a progress function
								if(progressFn && typeof progressFn == "function") {
									progressFn(prog,value);

								// if we passed a progress element
								} else if (progressFn) {
									$(progressFn).val(value);
								}
							}, false);
						}
						return myXhr;
					},
					data: formData,
					dataType: "json",
					cache: false,
					contentType: false,
					processData: false,
					complete : function(res) {
						var json;
						try {
							json = JSON.parse(res.responseText);
						} catch(e) {
							json = res.responseText;
						}
						if(successFn) successFn(json);
					}
				});
			}
		});
	};

https://www.youtube.com/watch?v=AZJfXr2LZXg