Changing image on UIButton when user presses that button on an iPhone

I am using Interface Builder, in which I added a UIButton to the view.

1. I defined the button selected by default and selected my image for the selected state (Use drop-down list in Inspector window to choose “Selected State Configuration” before selecting the image).

2. Create an IBAction in the controller and connect the button to that action.

3. Then see the code below:

  -(IBAction) toggleUIButtonImage:(id)sender{
      if ([sender isSelected]) {
         [sender setImage:unselectedImage forState:UIControlStateNormal];
         [sender setSelected:NO];
      } else {
         [sender setImage:selectedImage forState:UIControlStateSelected];
         [sender setSelected:YES];
      }
  }