Question: I created tens of **Label** over a **Group**, I added a right click menu for every Label, and then attached an event **listener** to the menu, then How I can get the exact Label which I right-clicked on via the menu item select listener (**ContextMenuEvent.MENU\_ITEM\_SELECT**)? Thanks very much

Answer: 
Produce XML output. Check the time taken and the file size.

Produce JSON output. Check the time taken and the file size.

Decide which is best.
JSON is good.

"the program will check often with the server". That is not required I believe.

Send an Asynchronous request using NSURLConnection and use NSNotificationCenter for notification services of iOS. So, when you get a response from the server, you can set a function to be called to use the data you need. [Check here for NSNotificationCenter usage](http://cocoawithlove.com/2008/06/five-approaches-to-listening-observing.html)