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;
}
})