I make some class. This class search some artist and return picture. After than I go to my class with player , where I create an instance of class and call the method and is passed artist. After i go to my tableview with audio So its doesn't work. Background still not changed and my app crashed. I don't know how I can fix that. http://pastebin.com/hUxqAuAh on this link my source code.

Error like this ( 2012-11-27 17:00:57.846 VKMusic[4959:c07] * Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'data parameter is nil' )

I want make like http://rghost.net/41831486.view on this picture.

upd: I found first problem. I must do like this NSString *encodedText = [artist stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];