How to trap the back button event
<p>I have a UITableViewController that launches a UIViewController and I would like to trap whenever the back button is pressed in the child controller, which is the class that derives from 'UIViewController'. I can change the Back Button title but setting the target &amp; action values when setting the backBarButtonItem seems to get ignored. What's a way to receiving some kind of notification that the Back button was tapped?</p>

<pre><code>- (void)showDetailView 
{
    // How I'm creating &amp; showing the detail controller
    MyViewController *controller = [[MyViewController alloc] initWithNibName:@"MyDetailView" bundle:nil]; 

    UIBarButtonItem *backButton = [[UIBarButtonItem alloc] initWithTitle:@"Pages"
          style:UIBarButtonItemStyleBordered 
          target:self          
          action:@selector(handleBack:)];

    self.navigationItem.backBarButtonItem = backButton;
    [backButton release];

    [self.navigationController pushViewController:controller animated:animated];
    [controller release];

}   

- (void)handleBack:(id)sender
{
    // not reaching here
    NSLog(@"handleBack event reached");
}
</code></pre>
