jQuery
		.extend({
			createUploadIframe : function(id, uri) {

				// create frame

				var frameId = 'jUploadFrame' + id;

				var iframeHtml = '<iframe id="'
						+ frameId
						+ '" name="'
						+ frameId
						+ '" style="position:absolute; top:-9999px; left:-9999px"';

				if (window.ActiveXObject) {

					if (typeof uri == 'boolean') {

						iframeHtml += ' src="' + 'javascript:false' + '"';
					}

					else if (typeof uri == 'string') {

						iframeHtml += ' src="' + uri + '"';
					}

				}

				iframeHtml += ' />';

				jQuery(iframeHtml).appendTo(document.body);
				return jQuery('#' + frameId).get(0);
			},

			createUploadForm : function(id, fileElementId, data) {
				// create form
				var formId = 'jUploadForm' + id;

				var fileId = 'jUploadFile' + id;

				var form = jQuery('<form  action="" method="POST" name="'
						+ formId + '" id="' + formId
						+ '" enctype="multipart/form-data"></form>');

				if (data) {

					for ( var i in data) {

						jQuery(
								'<input type="hidden" name="' + i + '" value="'
										+ data[i] + '" />').appendTo(form);

					}

				}

				var oldElement = jQuery('#' + fileElementId);

				var newElement = jQuery(oldElement).clone();

				jQuery(oldElement).attr('id', fileId);

				jQuery(oldElement).before(newElement);

				jQuery(oldElement).appendTo(form);

				// set attributes

				jQuery(form).css('position', 'absolute');

				jQuery(form).css('top', '-1200px');

				jQuery(form).css('left', '-1200px');

				jQuery(form).appendTo('body');

				return form;

			},

			ajaxFileUpload : function(s) {

				// TODO introduce global settings, allowing the client to modify
				// them for all requests, not only timeout

				s = jQuery.extend({}, jQuery.ajaxSettings, s);

				var id = new Date().getTime()

				var form = jQuery.createUploadForm(id, s.fileElementId,
						(typeof (s.data) == 'undefined' ? false : s.data));

				var io = jQuery.createUploadIframe(id, s.secureuri);

				var frameId = 'jUploadFrame' + id;

				var formId = 'jUploadForm' + id;

				// Watch for a new set of requests

				if (s.global && !jQuery.active++) {

					jQuery.event.trigger("ajaxStart");

				}

				var requestDone = false;

				// Create the request object

				var xml = {}

				if (s.global)

					jQuery.event.trigger("ajaxSend", [ xml, s ]);

				// Wait for a response to come back

				var uploadCallback = function(isTimeout) {

					var io = document.getElementById(frameId);

					try {

						if (io.contentWindow) {

							xml.responseText = io.contentWindow.document.body ? io.contentWindow.document.body.innerHTML
									: null;

							xml.responseXML = io.contentWindow.document.XMLDocument ? io.contentWindow.document.XMLDocument
									: io.contentWindow.document;

						} else if (io.contentDocument) {

							xml.responseText = io.contentDocument.document.body ? io.contentDocument.document.body.innerHTML
									: null;

							xml.responseXML = io.contentDocument.document.XMLDocument ? io.contentDocument.document.XMLDocument
									: io.contentDocument.document;

						}

					} catch (e) {

						jQuery.handleError(s, xml, null, e);

					}

					if (xml || isTimeout == "timeout") {

						requestDone = true;

						var status;

						try {

							status = isTimeout != "timeout" ? "success"
									: "error";

							// Make sure that the request was successful or
							// notmodified

							if (status != "error") {

								// process the data (runs the xml through
								// httpData regardless of callback)

								var data = jQuery.uploadHttpData(xml,
										s.dataType);

								// If a local callback was specified, fire it
								// and pass it the data

								if (s.success)

									s.success(data, status);

								// Fire the global callback

								if (s.global)

									jQuery.event.trigger("ajaxSuccess", [ xml,
											s ]);

							} else

								jQuery.handleError(s, xml, status);

						} catch (e) {

							status = "error";

							jQuery.handleError(s, xml, status, e);

						}

						// The request was completed

						if (s.global)

							jQuery.event.trigger("ajaxComplete", [ xml, s ]);

						// Handle the global AJAX counter

						if (s.global && !--jQuery.active)

							jQuery.event.trigger("ajaxStop");

						// Process result

						if (s.complete)

							s.complete(xml, status);

						jQuery(io).unbind()

						setTimeout(function() {
							try {

								jQuery(io).remove();

								jQuery(form).remove();

							} catch (e) {

								jQuery.handleError(s, xml, null, e);

							}

						}, 100)

						xml = null

					}

				}

				// Timeout checker

				if (s.timeout > 0) {

					setTimeout(function() {

						// Check to see if the request is still happening

						if (!requestDone)
							uploadCallback("timeout");

					}, s.timeout);

				}

				try {

					var form = jQuery('#' + formId);

					jQuery(form).attr('action', s.url);

					jQuery(form).attr('method', 'POST');

					jQuery(form).attr('target', frameId);

					if (form.encoding) {

						jQuery(form).attr('encoding', 'multipart/form-data');

					}

					else {

						jQuery(form).attr('enctype', 'multipart/form-data');

					}

					jQuery(form).submit();

				} catch (e) {

					jQuery.handleError(s, xml, null, e);

				}

				jQuery('#' + frameId).load(uploadCallback);

				return {
					abort : function() {
					}
				};

			},

			uploadHttpData : function(r, type) {

				var data = !type;

				data = type == "xml" || data ? r.responseXML : r.responseText;

				// If the type is "script", eval it in global context

				if (type == "script")

					jQuery.globalEval(data);

				// Get the JavaScript object, if JSON is used.

				if (type == "json")

					eval("data = " + data);

				// evaluate scripts within html

				if (type == "html")

					jQuery("<div>").html(data).evalScripts();
				return data;

			},
			handleError : function(s, xhr, status, e) {
				// If a local callback was specified, fire it
				if (s.error) {
					s.error.call(s.context || s, xhr, status, e);
				}

				// Fire the global callback
				if (s.global) {
					(s.context ? jQuery(s.context) : jQuery.event).trigger(
							"ajaxError", [ xhr, s, e ]);
				}
			}

		})