Navigation doubts in Iphone sdk
<p>I am facing a different problem in navigation ,i have three view controllers,bookselectionview,chapterselectionview and verseselectionview,the bookselectionview contains books of Bible if we tap genesis it navigate to genesis chapterpage
and if the chapter is selected from the view it navigate to the corespondent chapters verse view,i have close button in chapter view and verse view if the user tap the verse close button it wants to pop to the corespondent chpterview,that is like the back button in the navigation bar,but i created the custom button for that,my problem is when i tap the back button it cress the application.this is my code 
in viewwillapper of the chpterview</p>

<p>[button addTarget:self action:@selector(ButtonClicked:) forControlEvents:UIControlEventTouchUpInside];</p>

<pre><code> -(void)ButtonClicked:(UIButton *)sender{
        VersusSelectionView *detailViewController = [[VersusSelectionView alloc] initWithNibName:@"VersusSelectionView" bundle:nil];

    //detailViewController.firstString = firstString;
    // ...
    // Pass the selected object to the new view controller.
    detailViewController.selectedChapter=[sender.titleLabel.text intValue];
    appDelegate.selectedChapterIndex=[sender.titleLabel.text intValue];
    self.hidesBottomBarWhenPushed=YES;
    [self.navigationController pushViewController:detailViewController animated:YES];

    [detailViewController release];
}
</code></pre>

<p>the above code navigate t the verse page 
in versepage viewwillappear</p>

<pre><code>[button addTarget:self action:@selector(ButtonClicked:) forControlEvents:UIControlEventTouchUpInside];
</code></pre>

<p>in verseselectionview closebuttonclick</p>

<pre><code>-(IBAction)_clcikbtnclosetochptervew:(id)sender
{
[self.navigationController popViewControllerAnimated:YES];
}
</code></pre>

<p>when tapping close buon it pop the chpterview and crash the app.
any error in my code? please help me to do this.Thanks.</p>
