UIPageControl does not respond to touch, does not change dot

Question

I have a UIPageControl. When I click on a dot to change the page, nothing happens. Second dot does not get highlighted.

It works fine, however, when I scroll my UIScrollView. In that case the second dot is highlighted.

pageControl = [[UIPageControl alloc] init] ;
pageControl.center = CGPointMake(160.0f, 430.0f);
pageControl.numberOfPages=nPages;
pageControl.currentPage=0;
pageControl.hidesForSinglePage = YES;
pageControl.userInteractionEnabled =YES;

[pageControl addTarget:self action:@selector(pageTurn:) forControlEvents:UIControlEventValueChanged];

[self.view addSubview:pageControl];

This should be called when I change pageControl Value but it does not get called since it does not respond to touch.

- (void) pageTurn: (UIPageControl *) aPageControl
{
    int whichPage = aPageControl.currentPage;
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:0.3f];
    [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
    sv.contentOffset = CGPointMake(320.0f * whichPage, 0.0f);
    [UIView commitAnimations];
}