UIBarButtonItem Custom view in UINavigationBar

Question

I am making a custom bar buttons for uinavigationbar, I am using following code

 UIImageView *backImgView= [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"chk_back.png"]]; [backImgView setUserInteractionEnabled:YES];
UIBarButtonItem *backButton = [[UIBarButtonItem alloc] initWithCustomView:backImgView];
[backButton setTarget:self];
[backButton setAction:@selector(BackBtn)];
checkIn_NavBar.topItem.leftBarButtonItem = backButton;

The problem is it is not calling its action. What i am doing wrong?