handling errors from server side

Can you please tell me how to handle errors from server side. Fr eg. If want to handle something in the server and throw Exception in UploadHandler if that condt is not satisfied; is there a specific format on the returned values (something like dataprocessor) so that i can show appropriate alert to the user?


first create you server side validation

use file.error property

Current version does not allow extended error handling.
GetInfoHandler supports only specific error codes (-2,-3) to handle max filesize.
You may use code -3 and pass some error description.