Find iOS versions programmatically

#define iOS_VERSION_EQUAL_TO(version) ([[[UIDevice currentDevice] systemVersion] compare:version options:NSNumericSearch] == NSOrderedSame)
#define iOS_VERSION_GREATER_THAN(version) ([[[UIDevice currentDevice] systemVersion] compare:version options:NSNumericSearch] == NSOrderedDescending)
#define iOS_VERSION_GREATER_THAN_OR_EQUAL_TO(version) ([[[UIDevice currentDevice] systemVersion] compare:version options:NSNumericSearch] != NSOrderedAscending)
#define iOS_VERSION_LESS_THAN(version) ([[[UIDevice currentDevice] systemVersion] compare:version options:NSNumericSearch] == NSOrderedAscending)
#define iOS_VERSION_LESS_THAN_OR_EQUAL_TO(version) ([[[UIDevice currentDevice] systemVersion] compare:version options:NSNumericSearch] != NSOrderedDescending)


Let say check for iOS 5.0
if (iOS_VERSION_LESS_THAN(@"5.0"))