I'm using [MPMoviePlayerController](http://developer.apple.com/library/iOS/#documentation/MediaPlayer/Reference/MPMoviePlayerController_Class/Reference/Reference.html) in iOS. I'm listening on any errors it may have while playing videos. In my error handlers, I pop up an [UIAlertView](http://developer.apple.com/library/iOS/#documentation/UIKit/Reference/UIAlertView_Class/UIAlertView/UIAlertView.html). Sometimes errors may occur in quick succession of each other and thus multiple alert boxes will stack up. For a better user experience, I wish to not pop up another alert if an earlier one is still displayed.