Starting with iOS 5, there are two notification styles: banner and alert (the \"old\" style). A user can set which style to use for each application in the settings. However
You can use this line to query the current settings for notification style:
UIRemoteNotificationType* enabledTypes = [[UIApplication sharedApplication] enabledRemoteNotificationTypes];
You can check the enabledTypes and then instruct the user to change the notification style in the settings.
enabledTypes