Imagescrollview is showing black screen than images - iphone

Question

When clicking on gallery button it shows black screen
UIButton *galleryButton = [UIButton buttonWithType:UIButtonTypeCustom];
[galleryButton addTarget:self action:#selector(ScrollView:) forControlEvents:UIControlEventTouchUpInside];
galleryButton.frame = CGRectMake(0, 0, 30, 30);
UIImage *ime = [UIImage imageNamed:#"photos.png"];
[galleryButton setImage:ime forState:UIControlStateNormal];
UIBarButtonItem *gallerybutton = [[UIBarButtonItem alloc] initWithCustomView:galleryButton];
-(void)ScrollView:(id)sender
{
ImageScrollViewController *imagescrollviewcontroller = [[ImageScrollViewController alloc] init];
[self presentViewController:imagescrollviewcontroller animated:YES completion:NULL];
[imagescrollviewcontroller release];
}
- (void)viewDidLoad
{
self.view.backgroundColor = [UIColor viewFlipsideBackgroundColor];
[_imageScrollView setBackgroundColor:[UIColor blackColor]];
[_imageScrollView setCanCancelContentTouches:NO];
_imageScrollView.indicatorStyle = UIScrollViewIndicatorStyleWhite;
_imageScrollView.clipsToBounds = YES; // default is NO, we want to restrict drawing within our scrollview
_imageScrollView.scrollEnabled = YES;
_imageScrollView.pagingEnabled = YES;
// load all the images from our bundle and add them to the scroll view
NSUInteger i;
for (i = 1; i <= kNumImages; i++)
{
NSString *imageName = [NSString stringWithFormat:#"image%d.png", i];
UIImage *image = [UIImage imageNamed:imageName];
UIImageView *imageView = [[UIImageView alloc] initWithImage:image];
CGRect rect = imageView.frame;
rect.size.height = kScrollObjHeight;
rect.size.width = kScrollObjWidth;
imageView.frame = rect;
imageView.tag = i;
[_imageScrollView addSubview:imageView];
//[imageView release];
}
[self layoutScrollImages];
- (void)layoutScrollImages
{
UIImageView *view = nil;
NSArray *subviews = [_imageScrollView subviews];
// reposition all image subviews in a horizontal serial fashion
CGFloat curXLoc = 0;
for (view in subviews)
{
if ([view isKindOfClass:[UIImageView class]] && view.tag > 0)
{
CGRect frame = view.frame;
frame.origin = CGPointMake(curXLoc, 0);
view.frame = frame;
curXLoc += (kScrollObjWidth);
}
}
// set the content size so it can be scrollable
[_imageScrollView setContentSize:CGSizeMake((kNumImages * kScrollObjWidth), [_imageScrollView bounds].size.height)];
}
Any idea why it is not showing images but black screen. I am following apple sample code for scrolling images. Changes i have made is that they are showing two subview in scrollview. i am showing only one subview.
Thanks for help.