Navigation with UISegmentcontrol iphone

I have created an up/down arrow segmented control button on the right side of the navigation bar in my detail view. How can I use these up/down arrows to 开发者_StackOverflowchange views?

[mySegmentedControl addTarget:self action:@selector(mySegmentedControlTapped:) forControlEvents:UIControlEventValueChanged];
...

- (void) mySegmentedControlTapped:(id)sender {
    NSUInteger selectedOption = mySegmentedControl.selectedSegmentIndex;
    if (selectedOption == upArrowIndex) {
        // swap in "up"-ward view controller
    }
    else if (selectedOption == downArrayIndex) {
        // swap in "down"-ward view controller
    } 
}