Scrollview doesn't remains on the center indicator

- (void)viewDidLoad {
    
	arr = [[NSMutableArray alloc] initWithObjects:@\"Test1\",@\"Test2\",@\"Test3\",@\"Test4\",@\"Test5\",nil];

	
	UIImageView *img = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@\"bg_content_slide.png\"]];
	img.frame = CGRectMake(0, 20, 320, 85);
	img.contentMode = UIViewContentModeScaleAspectFill;
	
	
	[self.view addSubview:img];

	[self setScrollButtons];
	
	[super viewDidLoad];
	
}

- (void) setScrollButtons
{
	tagScrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 30, 320, 44)];
	tagScrollView.backgroundColor = [UIColor clearColor];
	[tagScrollView setShowsHorizontalScrollIndicator:NO];
	[tagScrollView setShowsVerticalScrollIndicator:NO];
	[tagScrollView setCanCancelContentTouches:NO];
	tagScrollView.indicatorStyle = UIScrollViewIndicatorStyleBlack;
	tagScrollView.clipsToBounds = YES;
	tagScrollView.scrollEnabled = YES;
	tagScrollView.pagingEnabled = YES;
	tagScrollView.bounces = YES;
	tagScrollView.delegate = self;
	tagScrollView.tag = 2;
	
	pageControl.numberOfPages = [arr count];
	pageControl.currentPage = 0;
	[pageControl addTarget:self action:@selector(pageTurn:) forControlEvents:UIControlEventValueChanged];
	
	int xaxis = 0;
	
	for (int i = 0; i < [arr count]; i++) {
		
		UIButton *btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
		btn.frame = CGRectMake(xaxis+80, 0, 160, 44);
		//btn.titleLabel.text = [NSString stringWithFormat:@\"%@\",[arr objectAtIndex:i]];
		[btn setTitle:[arr objectAtIndex:i] forState:UIControlStateNormal];
		NSLog(@\"%@\", btn.titleLabel.text);
		
		xaxis += btn.frame.size.width + 40;
		
		[tagScrollView addSubview:btn];
	}
	
	
	[tagScrollView setContentSize:CGSizeMake([arr count] * 220, tagScrollView.frame.size.height)];
	
	[self.view addSubview:tagScrollView];
}

- (void) pageTurn: (UIPageControl *) aPageControl
{
	whichPage = aPageControl.currentPage;
	[UIView beginAnimations:nil context:NULL];
	[UIView setAnimationDuration:0.3f];
	[UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
	tagScrollView.contentOffset = CGPointMake(200.0f * whichPage, 0.0f);
	
	[UIView commitAnimations];
}

- (void) scrollViewDidScroll: (UIScrollView *) scrollView
{	
		CGPoint offset = scrollView.contentOffset;
		
		NSLog(@\"offset is %@\",NSStringFromCGPoint(offset));
	
		CGFloat pageWidth = floor(scrollView.contentSize.width/pageControl.numberOfPages) ;
		//pageWidth = 190;
		
		int page = floor((scrollView.contentOffset.x - pageWidth / 2) / pageWidth) + 1;
		NSLog(@\"Page is : %d\",page);
		pageControl.currentPage = page;
	
}



- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate // called on finger up if user dragged. decelerate is true if it will continue moving afterwards
{
	CGFloat pageWidth = floor((scrollView.contentSize.width-220)/pageControl.numberOfPages) ;
	//pageWidth = 190;
	
    int page = floor((scrollView.contentOffset.x - pageWidth / 2) / pageWidth)+1;
	NSLog(@\"Page is : %d\",page);
    pageControl.currentPage = page;
	
}