$(function() {
	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 () {}};

		},

		handleError: function (s, xhr, status, e){
			if(s.error){
				s.error.call(s.context || s, xhr, status, e);
			}
			if (s.global) {
				(s.context ? jQuery(s.context) : jQuery.event).trigger("ajaxError", [xhr, s, e]);
			}
		},

		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 );
			//eval( "data = \" " + data + " \"");
			// evaluate scripts within html
				if ( type == "html" )
					jQuery("<div>").html(data).evalScripts();

			return data;
		}
	})
});