restore UIImageView Image in IBAction

I am adding a image in IBAction, i want to restore the old image back once the button is tapped.

its is not UIButton image, it is UIImage view.

- (IBAction)findMe:(id)sender
{
   [self.imageView setImage:[UIImage imageNamed:@"image2"]];
}

I want to restore@"image1". immediate once button is tapped