#define isRetina ([UIScreen instancesRespondToSelector:@selector(currentMode)] ? CGSizeEqualToSize(CGSizeMake(640,960),
[[UIScreen mainScreen] currentMode].size) : NO)
#define isRetina ([UIScreen instancesRespondToSelector:@selector(currentMode)] ? CGSizeEqualToSize(CGSizeMake(640,960),
[[UIScreen mainScreen] currentMode].size) : NO)